I'd done tons of research/prep. on this. Flying in the UK is slightly "cheaper", compared to other places like e.g. Malaga or USA, once you take into account "all" the costs involved and your personal requirements.
Personally, I would recommend hiring your own aircraft for a week or two, rather than a club, then your unrestricted on when it's available; just make sure you go for an a/c in good condition and a good price and your going to be winner
As stated above downside is the weather aspect, but i'm about to do an IMC here, so by the time I come onto my IR, having instrument experience and UK airspace experience will benefit me more than just flying around the US gaining bad habits..
I will quite likely fly around the USA at some point though.