Nothing wrong with T5, used it yesterday. Shops are perhaps even bigger rip-offs than anywhere else, it strikes one that if a realistic security risk assessment were carried out by someone who knows how Al Qa'ida operates the security staff would be a much higher potential risk to aviation safety than the passengers, and inward immigration is no worse than any other UK airport and better than a few.
But you simply have to ignore those downsides and it's a nice place to use.