I think you will find that it will depend more on you, than where you are on a big scale. Most UK areas, vary from street to street more than from town to town. So for example I live in southwest london in a nice middle class street, but three roads down is a council estate... Totally different area!
I've been postop for well over 30 years. In that time I've lived in many many places around the UK without any problems but then again I'm not hooked into the LGBT scene at all either.
I've heard of a few people having trouble everywhere, even Brighton, but on investigation its seems they have mostly been either, simply living in the wrong road (make sure you do your research before choosing a street), engaging in sex with risky partners, or openly heavily hooked into the LGBT scene. Either way increased visibility seems to be what made them most vulnerable.
In my experience the UK is a place where you can do almost anything in MODERATION and people will let you get on with it without any problem. That only changes if you become, loud, extreme, flashy, in your face, overfriendly, or any other non "middle of the road" thing. In short if, like me, you are an ordinary, respectable, middle class professional, no one will bat an eyelid, because they will be too busy complaining about the loud music from number 47, and the man with the huge mercedes who blocks up three parking spaces!