We flew JetBlue in July from SFO to IAD, and it was one of the best coast-to-coast flights we've ever had! We had been flying on United, but after JetBlue, we plan to use up our United miles on solo flights for various family members, and bid United buh-bye!
With a long flight, though, we found that we maxxed out the programming on the seatback TVs, and were watching the same shows over again. That was a bit disappointing. But, in general, what a great feature!
The seats were very very comfortable, and we had good legroom. The crew was super nice, and snacks were terrific too; when my youngest daughter couldn't make up her mind about which snack to select (imagine! being able to have choices of snacks anymore!), the crew member just gave her one of everything!
(The only airline that I think can give JetBlue reasonable competition is Virgin America...but they have much more limited flights and a big downside to them is that they charge for snacks--boooooo! We liked flying Virgin America a few months ago. Coming from SFO, I'd pick Virgin over JetBlue if their price is lower (which it was--by a considerable margin--when we flew SFO to IAD at Thanksgiving), and *especially* if there's a nonstop flight, which JetBlue doesn't have from the Bay Area to Orlando).
Of course, it's all a matter of where you're flying from, and those are my little aspects. But yes, JetBlue has a definite thumbs up in our family! (And I'd say, if you have headphones, bring 'em)