Planning a trip to Orlando in early summer. Had planned to go American so I could leave from Heathrow, but looks like I'll have to bite the bullet and schlep all the way down to Gatwick. Which is a better choice for economy? For my travel dates, both cost almost exactly the same. Virgin, however, does give me a later flight back (I have to fly back on my mother's birthday, so I'd like to make it as late as possible).
Normally, my transatlantic flights are business related so I get to fly business class, but this is on my own dime and it's high season, so it will be a coach seat.

Although not specifically London-Orlando, we flew Sunday LHR-Boston on a completely full BA 747 in lowest of 4 fares. Had 3 seats in middle of 4-seat section in back of plane - so we experienced the potentially worst BA had to offer.

It was a fine flight! Seats were somewhat more comfortable than US domestic coach seats. Seatback movies - about 10 choices. Cabin service was efficient and the food was actually edible - they fed us twice on 6 1/2 hour flight.

So while not actually enjoyable, it was tolerable - which is about the best you can expect on a flight in a sardine can with 350 other people!

Some of VS's planes have very tight legroom in coach, even 30" ones. Not all, so you can't tell if your flight will be one.

AA may still have More Legroom Through Coach on the flight you choose, but even if it doesn't, it will still have 31-32". But of course they don't fly non-stop to Orlando.

Icelandair does go into Heathrow from Orlando but you have to change planes in Iceland and they only fly three days a week. As for BA, ask if they have any seats available in Economy Plus when you check in. Full free bar in economy with BA--so they advertise.

When I flew BA last summer, the pilot announced, we are 20 minutes from landing so I will be turning on the fasten seat belt sign now. I was in line for the toilet at that time. The flight attendant walked me to the Business Class toilet and said with her British English as she opened the door, "But do hurry." Real nice folks at that BA. Also, when you check in at Orlando, ask how much a business seat would be going over only. Flat beds in BA Business. Coming back is a day flight so I would rather watch movies and talk to people--not sleep.

The Icelandair flight is an interesting option, but on any of the dates I could fly to the U.S., I would have to stop in Iceland and Minneapolis, with a total flying time of over 15 hours. And the cheapest seat was actually $500 more than with BA/Virgin.
I have done the flat bed thing on BA to and from Chicago. It's nice, but I'm not going to spend the extra $$ at this point...I'd rather go biz class when someone else is paying.
Spending as much time as possible with my mother is the priority for this trip, so I think I will go for Virgin which has a late evening departure available for my return. BA doesn't.

You can check www.v-flyer.com or www.seatguru.com for seat ratings. Your aircraft should be the 747-400 (LGW version). I believe VS still sells exit row seats in economy class for GBP50 or USD75 one way. You could also look into the cost of flying in premium economy. If you go with PE, I think the upper deck is better.