I'd definetly echo Chilli-Monster's words.
Faultless, professional, and they really care.
If you are going for a PPL only then you get a FAA one (trained to JAA standards) then use the ICAO priviledges of it when you return to the UK.
If you are going for a zero to hero, then you do the FAA CPL/ME/IR and then go back to the UK to convert which you have to do anyway unless you go to Florida (not sure if you can get an IR in Florida though).
You also have less of a hours requirement with the JAA/CAA to attain a licence when holding a FAA one. Therefore, easy on the pocket and £1 = $2 you can't beat it and no landing fees.
Only thing you will have to put up with is some snooty individuals looking down their nose at you with respect to doing your training stateside, to them I'd answer "a 172 stalls at the same airspeed in european air as it does in yank air, and guess what, I paid a third of what you did".
California beats anywhere else for weather, x/c destinations (San Diego, Las Vegas, San Fransisco, Santa Barbara).
Also Seosamh can give examples of his former students now working both in the US and in Europe.