General conclusion from all of the published leaks is that GCHQ punches (in technical capability and general quality of work) way above its weight class (funding and presumed staffing levels); they also seem much more willing than NSA to be completely unbound by any idea of domestic user privacy. Which is fitting for a country with the number of CCTV cameras they have.
Although, in effect I think you are right about GCHQ, that whole CCTV thing is pretty much a myth founded in a deeply flawed study focussed on a street in Central London. 90% of CCTV is privately owned, and if you step out of the metropolis CCTV is no more abundant than anywhere else. I suggest you stop using that argument with regard to the UK as it undermines your absolutely valid post.