When i saw a band recently at the Astoria they were on stage at 8.15pm. This is because the Astoria put on a club night and they wanted to clear out everyone who had been at the gig by 10pm! I got in at about 9.15 expecting the main band to hit the stage at 9.30ish so I missed everything except the encores. So my advice is check with the venue when FB&tCs are on stage or you may be very disappointed.
This may make me sound like an old women but i like it when bands get on stage early, if they don't get on stage till 9.30-10pm i'm really tired and have to miss the end of the show to catch my train.
Kinda regreting buying the Astoria tickets now - should have gone for out of London. The last time I went to Astoria (over 11 years ago) my wife got knocked out by a crowd surfer and got five stiches in the head - mind you it was a Sacred Reich gig!
Alway perferred Brixton and Hammersmith for London gigs - saw Pixies at the Acadamy in 91 - top place for gigs!!