I had a very good experience, as a Sqn Ldr you get a one bedroom flat and Mears were very good at finding somewhere suitable and doing all of the march in administration etc. For the two weeks that I had to wait (as the first option they found fell through) they put me up in a nice hotel (holiday inn, small room but good facilities and just off Kensington High St). Everyone I know that was assigned into London recently got a nice flat in a decent area, that they were happy with.