Will be going to Europe (Ireland) for the first time in the spring of 2014 and just started to look at flight availabilities. I will be flying from Jacksonville Fla to Shannon Ireland and when looking at flights have noticed that flights with the exact same departure/arrival times, layovers show up but are listed under Delta, KLM, and Air France (Code sharing?)For the most part the prices are exactly the same or within a couple of dollars. Question: Besides collecting frequent miles are there any advantages I may not be aware of that I should consider when making a reservation with one airline over another for the same flight?
If it is about collecting miles sometimes there are promotions limited to only a certain set of flight numbers. So e.g. if Lufthansa excluded flight numbers from 5000 and up you know they only allow "triple miles" etc. on flights operated by their own aircraft, but not on e.g. United. But nowadays this rarely happens. Which of the three partners you mentioned is the operating carrier? Whose equipment will be used, whose services will you be exposed to? Of the three you mentioned clearly KLM offers the best service e.g. Sometimes when a flight has to be cancelled or something else happens you might have a very slight advantage if you've booked with the very airline that's actually operating the flight.
I know of no advantage or preference. I go with price and schedule.
Delta is the primary carrier
Might be cheaper if you book directly with Delta at their web site.
In case of delay or cancelation the European based carriers are bound by law to house and feed you. The US carriers aren't. This difference was apparent during the Icelandic volcano shutdown a few years ago.
Delta and KLM/Air France have a completely pooled schedule trans-Atlantic. Almost any site you use will specify which airline will actually operate the flight although all three sell tickets under their own numbers. Points are awarded for all flights by Delta or the KLM/Air France plan as the customer specifies. Delta's plan is relatively simple: All miles (or pretty nearly) are created equal. No expiry date, either.
Service standards are pretty similar, too, so far as I have experienced in economy. I like the selection of movies on Air France and being offered champagne even at the back of the plane, but Delta is okay and so is KLM (which has the most jovial cabin crews, but that's idiocyncratic too.) Price and schedule convenience matter far more.