I'm another guy who thinks Princess is the most comfortable for gay travellers. I've done just over 40 cruises, on all the major lines (except Royal Caribbean) and certainly feel at home on Prncess. The FOD get togethers are alway early on, with champagne provided. Stewards do not bat an eye when you requests the bed together. On many occasions, when entering the any time dining room, and requesting a table for 2, the maitre de has indicated that there is still room at a large table, with all those seated being male couples! Invitations to other special get togethers are always inclusive of your partner.
On HAL there have been glares over similar things, especially from the Asian staff. Not once has an officer attended the FODs, while on Princess it is common. Getting a mention in the daily paper for an early get together during a cruise is denied or refused. I can't really comment on Celebrity as I have only done 3 cruises there, but I felt their attitude was forced rather than genuine.
I've get two more cruises booked, a 10 nighter on Emerald in January, and then 32 days on Star in September. I guess I'm a Princess fan!!