Yes - we've flown with them quite a few times, and they are fine.
You get a few les, we went to Orlando from Gatwick in Oct this year, and due to problems with the brakes, we sat on the tarmac for an hour before we took off, but this could happen with anyone.
The planes themselves are quite comfortable, leg room is not too bad, (and DH is 6'4"!), they give you pillows, blankets and a little welcome pack with earplugs, toothbrush etc. They also give the kids bags with puzzle books and things.
There is a good choice of films and tv shows, and going out this year we had the game system as well - although the one in my seat didn't work.
Food is Ok - normal plane food - not brilliant but adequate, but we didn't think much of the kids' meals, basically just junk food, so we would not order those again.
If you are on your honeymoon or anything, it might be worth mentionning to the cabin staff. 11 years ago, we flew back from Miami on our honeymoon, and our lights and TVs did not work. The steward asked if we were on our honeymoon, and after checking with his supervisor, moved us to premium economy. Wow - that was great!
The only downside really is the flight back. Although the seats are comfortable if you are awake, I cannot get comfy enough to sleep in them. And, the flights are at night, so after flying home with no sleep, I am like a bear with a sore head the next day. I am trying to persuad DH to upgrade coming back next time, but I don't think its going to happen!
Have a great time anyway - don't forget you can book your seats in advance, and check in either online 24 hours before you fly(although this too was not working the day we flew), or drop your cases off the night before (twilight check-in). We have always done this, and other passengers have said it is like a madhouse if you check in on the morning you fly.
Also you can check in early on your return at Downtown Disney the morning of your flight. By doing this, you drop your cases off for the day, but more importantly, you miss the queues at the airport, which another passenger told me were terrible.
Hope this helps!