Only flown first class once- "Premium Business" which is what Chilean airline LAN used to call it (they have since merged with Brazilian airline TAM to form LATAM). Booked it by accident when me and Mr Jam had a trip to Santiago booked and then got a bit of a windfall and decided we'd spend it on a jaunt to Easter Island. Got the cheapest tickets then checked the confirmation email and found that by some pricing quirk we'd paid about £350 each for a five-hour first class flight on the muh'fuckin' Dreamliner. Get in...
It was amazing as well- nice comfy pods with back massagers in the seats, big tellies, complimentary socks and blankets and eye masks and pillahs, those polarised windows where you can control the tint with buttons, and proper nice food (Steaks On A Plane) with decent wine and proper metal cutlery and tiny white linen tablecloths.
The only bad thing was having kids from Economy wandering in to gawp at us like we were in some kind of posh people zoo- the ticket price should have covered the wages of a snooty concierge at least.
I bet BA isn't that good. I bet Air France is amazing though, judging by the quality of the sandwich I once had in Economy. That was the best sandwich of my life, I still dream about that sandwich. It had posh ham and two types of posh cheese and hazelnuts and it was even better than the Steaks On A Plane. I have tried to recreate that sandwich but the identity of Posh Cheese #2 eludes me.