I would think that the transit of passengers at Brize should save about an hour over the time from aircraft to leaving the terminal.........
.....after all the most important thing after a spell in a hot and sandy place is to get home as quickly as possible.
At East Midlands I've seen troops get off the DC10 and straight onto coaches which took them back to their unit direct, (the bags followed on later on a lorry) so it's actually pretty efficient. I've not seen the process at a really large airport, but we don't tend to use the really big ones anyway.