Wise words from many there. If I was to do it all over again I would probably want to allow at least 4 but preferably 5 weeks to do a PPL, and thats without the theory too. This way you would have the odd day here and there to relax and soak it all up, and also would have spare days in case any flying was cancelled due to bad weather or maintenance issues.
In regards to the weather, we had 6 awesome storms while I was out there, and a tornado just 3 or 4 miles away which we watched, and I can assure you all that some of my flying was rough and bumpy, and we had some pretty good cross winds to deal with so I would say it does give you a taste of what to expect in the UK aviation bag.
I would definitely agree that the attitude to flying out there is very positive indeed, and the extra freedom you have with regards to landing at other airfields, and night flying makes the whole experience totally worthwhile. I was disappointed to learn that there is practically no night flying in the UK until winter as most aerodromes close. In the USA you can practically land where you like, and when I was flying down to Stuart International (which was closed) at about 11:45pm I tuned in the Control Tower frequency, pressed my PTT button 7 times and the entire airport just iluminated for me like a giant Christmas Tree. It was one of the most incredible experiences of my life and something you would never see here. I landed my little PA28 at this huge airport, taxiied about and then took off and went on my merry way. AWESOME.