Deciding on flights input appreciated

Heathrow and I don't get along very well. Each time I changed there, the flight into Heathrow was late. I made the connection but my luggage didn't. Because these flights were all on one ticket my luggage was eventually sent to me. However, I was at my apt in Paris and not continuing my trip as a vacation. Others might have different experiences.

I'd personally go with the Delta flight because it has the non-stop to Rome. The return flight layover time is below my bare minimum of 3 hours but it is probably doable. Do you have Global Entry or the mobile passport app? That might get you thru passport control quicker.

To me overnighting at Gatwick would be the least appealing option, particularly if the flight costs are close.

Definitely Delta-nonstop to Rome and lots of good places to eat during the layover. Only one connection-American is 2. Every connection increases chance of lost luggage and flight delays that cause you to miss later flights.

Having flown to Europe from OAK and SFO but not from SMF yet, I’d vote for the second choice out of SMF even with the one longish layover in Atlanta. SMF is such a comfortable airport to navigate and traffic getting there for us adds no pre trip stress.

Are these flights weekday or weekend because that makes a difference for us with getting into the Bay Area and traffic?

Call this a "possibility" rather than a "suggestion" - you could fly from SMF to LAX (Southwest) then fly non-stop LAX to Rome on Norwegian.

I would pick the Delta flight. I try not to do two stops, as there is more room for things to go wrong. Also, on the American flight, the layover in London is really short and leaves no room for error. Even though the Delta flight has a long layover, it will still be less time than spending an extra night in London on the way like the Norwegian flight. Have a great trip, I have been eyeing that tour!

Just curious.....are you using skyscanner? Kayak?

How much sleep will you get before that 6:30 AM flight? There's no way I'd start an overnight trek to Europe with a 6:30 AM departure.

I would suggest Norwegian into Gatwick and Easyjet on the connecting flight. Easier goes to just about every desirable city from BTW very inexpensively.
You also have.San Francisco International as an alternative airport. There are.many, many non-stop flights into European gateway airports from there.

I'd do the Delta flight via Atlanta: fewer connections, no overnights in between. Is there a return back to SMF from Atlanta later in the day in case you miss your connecting flight in Atlanta? I doubt you'd miss it unless you are really late into Atlanta. It would make me feel better to know there's another flight 2-3 hours later.

The tour(s) is in May. These are great suggestions. We are leaning toward the Delta flight. Sacramento does not have a lot of one stop options, and zero non-stop. We love non-stop and have a favorite hotel a few miles from Gatwick, but otherwise, you are right, that Norwegian option does not make much sense. I will research the connection from Catania and maybe save an overnight in Rome. I am using both Kayak and Google flights. I will check Skyscanner as well. If we do Delta with the 2 hr 43 minute layover inbound, all the more reason to sign up for Global Entry. I will check later flights from ORD to SMF but even if not, overnighting in Chicago would not be a dealbreaker. As for a 6:30 AM departure-we never sleep well before travel, so we’d be up anyway, and we both sleep pretty well on airplanes. And SFO as an option-we have done it but getting there adds another layer of uncertainty-Bay Area traffic needs to be seen to be appreciated.

Minutesuites offers day rooms at the Atlanta airport in terminal B, where you can get away from the bustle in the concourse, relax in a quiet environment, even take a nap if you're so inclined: https://www.minutesuites.com/.
We've used them a few times during extended layovers at the airport between connecting flights. Another reason to consider the Delta flight.

I would hesitate to book Alitalia that far out (and verify the Delta flight is not a codeshare with them) because that airline is on v. shaky financial ground and who knows what's going to happen with them in 2019.

For what it’s worth we fly from the west coast to Europe and break up the flight with an overnight stay before going on to our final destination. It seems to be less wearing on us. We started flying this way when my husband got a guide dog. We met friends for the Sicily tour. They flew Norwegian from LAX to Barcelona and had a few days there on their own. Then they flew Ryanair to Palermo. Going back they flew out of Catania to Barcelona and then Barcelona to LAX the next day.

I guess the "overnight stay" between flight connections is a personal preference. My preference is to get between destinations as directly and quickly as possible (unless the airfare is sky high or the connection is terrible - to me, a 2:43 connection is not terrible unless there is NO good option to get a later flight home and I HAVE to get home that night). An overnight stay in between means one ore hotel check-in, one more airport security check, one more airport day. I prefer to minimize all of that - get it all out of the way, not prolong the agony. Again, just my preference.

The 1 hr 40 minute layover in Heathrow is a little dicey in my opinion given the UK's lack speed in their passport control areas. It looks to me like the Delta itinerary is better.

Norwegian has direct flights from OAK to Rome, but they're on Tuesdays and Saturdays only.

The passport delay at Heathrow should not be involved here, this is an airside connection going through to a Schengen country, with no British immigration. All that would have to happen in Heathrow is an additional security check.

"There's no way I'd start an overnight trek to Europe with a 6:30 AM departure."

For those of us not in gateway cities, this is often unavoidable. I often have to take the 5:15A flight out of my local airport which only has a few flights a day to connect to international flights. While I've driven to the airport (an hour away) a time or 2 that means leaving home at 3:30 so now I usually stay that night in a hotel located near the airport.

Norwegian from LAX to FCO sounds very good if you fly Premium Economy.

About the 6:30am departure.

I don't know if you can do this or would want to do this, but now that I am retired, I can almost 100% eliminate jet lag by spending the two weeks before a trip gradually moving myself 3 or 4 hours onto Europe time. So, a 6:30am departure is like lunchtime to me the day we leave home. This works for me despite being exhausted on arrival in Europe due to never being able to sleep at all on the long flight from Minnesota.

I vote Delta. We always fly Delta to Italy these days.

How important is the premium economy to you?

I’m no expert on the topic but I don’t believe any of the US airlines offer a true PE product on their domestic flights. So both the American Air and Delta options you listed are likely a combination of extra leg room economy on the domestic and connect with PE on the international segment. Which leaves you with the Norwegian option for true PE. Based on the seat guru measurements Norwegian seems to offer more legroom than either of the US based options.

Delta.

AA has two layovers. I would never want that.

Norwegian requires an overnight stay meaning you'll have to deal with going to the airport twice arriving hours earlier and going through security each time and enduring the immigration lines at LGW as you'll be entering the UK just to stay overnight. Too much of a pain for me plus you'll have less time in Rome.

While Delta has 5 hours in ATL, at least you won't have a second layover nor will you have to overnight in another city. So Delta wins.

When you book airfare this early there is a good possibility that the routing of your flights will change or that a leg of your flight might be cancelled. The airlines may or may not notify you of the change. If you do book now, keep an eye on your reservation so that you have time to recover from any unforeseen changes by the airline and rebook.

The premium economy is important to us. Just that slight increase in leg room, the amenities, the drinks, the early boarding, dedicated bins-all add up to value for us. Can’t go back to economy and we would fly business class if it was not so darn expensive. So, why book this early? The premium economy seats are limited and selling out fast. And, there are three of us as my wife’s BFF is going along. I looked at all this good advice and we chose the Delta option. The American flight looked good at first blush but you are all correct-those two layovers with the short connection in LHR are deal breakers. I tried to talk my wife into flying earlier in the week on Norwegian, spending a few days in London, but did not prevail as we were there last summer, and, given our schedule we will be away 3 weeks which I’m finding is her limit. And overnight in Gatwick did not make sense as one of you pointed out; going through immigration, security, just a big hassle. I could spend months in Europe, but, as they say, happy wife, happy life. Flying same day from Catania- could not make it work, price was exorbitant, connections problematic, so we will overnight near FCO. Found a nice looking hotel and spa, a bit pricey but at this point.... https://www.qcterme.com/en/roma/qc-termeroma-hotel. Thanks all! Italy here we come!