As far as their economy service goes, they are much the same as Virgin and other scheduled airlines, and offer slightly more leg room than most of the charter airlines. They also fly into Orlando International, whereas the charter airlines tend to fly to Sanford (which is about an extra 30-45 minutes drive).
BA do have a premium economy seat - it's called World Traveller Plus - but I don't think it is available on the Gatwick-Orlando route. This may change in June 2004 when BA refit the planes on the LGW/MCO route to the new Club World seats. The difference in price between BA's World Traveller (economy) and World Traveller Plus is generally much greater than the upgrades that the charter airlines charge for their upgraded service.
We've just booked our seats for August 2004 and after much consideration decided that Travel City Direct's Sunshine First was the best option for us. It offers lots of leg room (54 inch seat pitch) and a small (child-free) cabin, which hopefully will be nice and quiet. It wasn't a cheap upgrade (£350 per person) but as we are going with my parents on their one and only holiday to Orlando we decided to treat ourselves. We did consider Virgin's Premium Economy, but I don't think it offers good value-for-money, so we opted for TCD.
Regards
Rob