I have flown with Thomson Fly to Natal and back from Gatwick. I have to say for economy class, it has one of the more comfortable. I haven't flown BA for years, so can't compare with current levels of economy comfort, but I did fly Etihad to Thailand last year, and to be honest despite the supposed in seat entertainment, Thomson was better for comfort, because on none of the Etihad flights did the entertainment system work properly for more than a few minutes at a time. The seating was closer in pitch on Etihad too. The major downer with Thomson is that unless you purchase it at the time of booking, you don't the in-flight meals. You can buy sandwiches and such, like on Easyjet, but you have to suffer being surrounded by people eating their hot meals.