PIK3141 - totally agree, although problematic for high-volume airports. Also needs a 'Chinese Wall' betwen arrivals and departures
liquid sunshine - no probs with shops per se here, BUT in most UK airports that means NO waiting areas. By all means have shops, but the main function for an airport still is to get pax from landside to airside and on an a/c with the least hassle and delay.
benlapworth - if you are looking to benchmark Birmingham T1 (which admittedly I've never been to), then you should perhaps look outside the UK. With the exception of LCY, there is not one reasonably well designed and managed (the latter perhaps being the more important) airport I know of in the entire country. They are all badly designed and managed by people whose prior management experience must be in running abattoirs. Horrid. The lot.
A bit more to your query:
STN: a mess, mostly for three reasons:
a) runs apparently well beyond capacity
b) security mostly understaffed
c) absurd up-down-sideways corridors to/inside the terminals
Access is reasonable, although not enough lifts from train platforms to terminal
LTN: as others have said here, used to be OK, but since they've built the new terminal, a joke. Nothing to add to Paxboy's comments
East Mids: would make any sub-Sahara country feel ashamed.
Common unpleasant factor are the tiny LCD screens giving flight info and the sometimes very late gate announcements. In STN it is sometimes almost physically impossible to get to the gate on time. Seem to be another BAA
ploy to increase pax time in the shopping areas.