In my opinion, the biggest advantage to doing a PPL (or any other licence) in the USA, for a Brit, is that you've removed yourself from the home environment, and they have really excellent weather availability in placess like Florida or Arizona.
So, you can reasonably hope to do courses on the basis of 7-10 hours of flying per week. That sort of intensive flying, really gets the learning curve nice and steep, so there's a good chance of doing it in minimum hours.
If you end up doing a bit of further training back in the UK, well so be it - that's fun (as all flying training should be) anyhow.
I did my PPL(M) in the UK and took a little over minimum hours but about 9 months, my PPL(SEP) in Florida in a fortnight and minimum hours, and my CPL in the UK in 18 months and somewhat over minimum hours. I primarily blame the slow learning curve caused by doing things at a lesson (or often less for one reason or another) per week.
So, there's much to be said I think for learning in the USA - just accept that things at home are different and if you've not actually flown in the UK much before, you've some additional learning to do.
G