There are several aspects to flying an aeroplane. There are the basic motor-skills - making it go where you want, which I would say were perhaps the most difficult bit of learning to fly initially. It doesn't really matter where you learn these.
There's navigation which is also quite tricky. Part of this is the basic 'pilotage and dead reckoning' skill - learning what to look for and making sure you fly accurate headings with the correct checks (it doesn't matter too much where you learn this), then there's knowledge of the surrounding area and knowing that the lake over there is Blah Lake and that road is the A53 and so on - which you can only get by doing a fair amount of flying in that area.
There is also RT - which you only really get the hang of with experience. RT in the states is quite a lot different from this country, so really you would be better off doing that in this country.
There's weather - the weather in the UK is quite a bit different to the weather in the states and the knowledge of where to expect clouds (over the Pennines) and how to avoid them (staying to the east of the Pennines, for example) is only something you'll find out over here.
And there decision-making. It's a beautiful day but is it too windy to go out flying with this girl I'm trying to impress now that we're at the airfield and loads of other (more experienced) pilots are flying? This really only comes with hours and a few scares!
I learnt over in the States (at Ormond beach, which was OK - the teachers were good, however having said that, there were aspects of it which I didn't like, and I have to say I wouldn't go back for more training there). When I started flying back in the UK, I was not confident about navigating or talking on the radio here. To sort these problems out I did an IMC course here, which was 15 hours of navigating by navaids, talking to ATC and flying with an instructor in some pretty awful weather conditions.
If I were going to do this again, I'd learn in the states then spend several hours flying in this country with an instructor to learn about flying over here. That way, you'll get more hours for your money.