I did my PPL in the UK, started in Sandtoft and finished at Newcastle. Whilst I felt the standard of training I had was excellent, I found the entire PPL was spread over 18 months. I was not constrained financially, and dedicated around 6 weeks of vacation time to sitting 'waiting for the weather' at airfields, and it was only through excellent staff at both airfields changing schedules for me that I eventually got through the skills test.
If I was to do it all over again, I would have gone to the US and completed the course in 3 weeks and then returned to the UK and performed remedial training at a mixture of controlled airfields and grass strips over a week or so.
I have flown abroad in a few countries since I completed my PPL and feel it doesn't take a great deal to adjust, you just have to be aware of the differences and spend an hour or so with an instructor to become familiar (well at least as a low hours PPL).