I did my CAA PPL with UKFT a long time ago, (1997). I passed, but the flight test was a joke, ann the 'examiner' never got around to doing the oral test. It only took me an hour to get flying back in the uk, but over the next couple of years, some significant gaps in my skills showed up. They were not handling skills, I've always been good at flying the plane, but checklist procedures and radio work was lacking.
I was my instructore first pupil, and though we got on well, it dawned on me just how superioir an instructor can be when I did my mulit rating a few years later in Australia with an ex DC3 pilot with thousands of hours.
Anyway, I must empahsise that I do not know what UKFT is like these days as I'm sure the staff have all long changed, but my advice would be
'do everything possible to learn to fly in the UK'
Not because of the weather, but you are more likley to experience a better attitude towards flying, not a 'kick the tyres and lets go' attittude. Also you won't be like a beginner when calling London Info for the first time!
By all means go stateside, but only once you are qualified and can enjoy your skills by touring.