I stayed there last May, I pretty much spent a whole day in the lounge (better than a room, has free drinks and food and is a larger room with comfortable chairs to sit on). I had my trusty 80-200mm lens and that was fine for pretty much 737-200 and up. Your main problem is that if the sun comes out, your best bet is by the approaches, also, I'm pretty sure that when the 09's are in use, no aircrafts except MAYBE a heavy 747 or 340 might roll by after touchdown. Still it is a cool hotel, especially at night as you have a wonderful view of tons of BA 757/767/320 tails all lit up at T1. Cheers and enjoy your stay, it's a fine hotel!
Think before you type!