We hope to spend 4 or 5 nights in Luzern with day trips to surrounding small towns and scenic areas. From there, we are headed to Milan. Questions:
--Should we go back to Zurich and spend a night before taking the train to Milan? Or is there a simpler option directly from Luzern?
--Have read very different opinions on whether to take the Bernina Express or different train options? Pros and cons?
Mary, There is no need to go anywhere first to catch a train to somewhere. Trains are an interconnecting network. There are 1838 stations in Switzerland, and you can travel by train from any one of those (including Luzern) to any other one, or to most other places in Europe (including Milan).
Go to the SBB (Swiss Federal Railways) website: https://www.sbb.ch/en/
Enter from: Luzern, to: Milano Centrale, and your desired date and time and click on [Search].
And it will show you all the options. There is roughly 1 train per hour, and it takes 3½ hours.
The SBB website always find the quickest route, which is in this case the main line to Italy through the Gotthard tunnel under the Alps. The longest rail tunnel in the world.
The Bernina route is an alternative route that goes over the Alps, and is very scenic. It is however in the eastern side of Switzerland, a long way from Luzern. If you want to go that way, add "via Chur Tirano" to your search and that will force the routing. This will take a lot longer (10 hours+). I would not try to do that in one day. If you want to go that way include an overnight stop.
A scenic alternative that doesn't take ten hours is, instead of taking the low level Gotthard tunnel, to take the old rail route in the high tunnel. To do that, simply specify "via Goeschenen" when you search for a connection on the SBB website. Time penalty is about one hour, but the line is much more scenic.
There's even an expensive dedicated scenic service called the Gotthard Panorama, that involves a boat ride out of Luzern followed by a train on the aforementioned route. Worth a look. It takes you to Lugano, from where Milan is a little over one hour further.
The Bernina Express is out of your way. But like the poster above, I would suggest the Gotthard Panorama Express, a special train that takes the older "high" route through the Alps rather than using the tunnel.
It only runs in high season ( April to 20 October) and connects Luzern with Lugano by boat and train, with one trip each day. The southbound trip departs Luzern around 11 am for the boat trip. If you do not care to ride a boat, you could meet the train at Flüelen for its 14:10 departure to Lugano. At Lugano you change to an Intercity train for the short trip to MIlan.
