I would agree with Stroller, learn where you are going to fly.
I learnt on the South Downs but since then (for the last 2 years) have flown only abroad.
Now I have come back to the South Downs I am finding that a good grounding (at Sky Systems) was VERY useful. It is helping me 'pick up where I left off'. This is because flying in the Alps is very different from flying on the South Downs on a gusty day. Not more or less difficult, just different. At present I am not very good

( but the training I received is gradually coming back and without it I am sure I would be finding it even more difficult!
In response to the arguments about BHPA schools, all I can say is, on a practical level if you have a BHPA rating this is recognised abroad and it means that you can (easily) fly the 'regulated' sites as well as the unregulated ones. ie it opens up more options - always a good thing in my book