Having flying in the UK and US heres my 2p worth, I got my intial JAA PPL in the US at a school owned by a Brit instructor.
Cost - You will definitely save money! Hours are cheaper and acoomodation is also cheap (I went to California), even taking this into account I saved I lot of money. I went for a month passed in 62.5 hrs and it cost me about £4000, in the UK it would have cost me nearly twice that for the aircraft & extra instructor time required at my local field. On top of this you wont be driving up and down to the airfield to be sent home and wasting time and money...having said this see 'Weather'
Exams - Yes could not agree more. If you are going to go over there then have all your exams out of the way BEFORE you show up! I did it with the JAA PPL and also when I did my FAA IR, if you arent going to then add another couple to your course time!!!
Weather - I cannot speak for Florida as never flown there but I think there are a few misconceptions about the weather in the US. Flying round CA you can basically find whatever weather you want to fly in, whilst PPLs were marvelling about the weather around Longbeach we went off finding A/Ps with dodgy wethaer to practice actual instrument approaches into instead of being under the hood all the time - bloody good fun! They even have ski resorts you can fly into, its pretty weird being sat on a snow covered mountain looking down at blazing hot desert...
RT - yes it is different but if you can handle the RT at somewhere like Longbeach which has 5 active runways then I think you can handle a grass strip somewhere in the UK countryside <img src="redface.gif" border="0"> ) No one I have spoken to has had any trouble picking it up, it just like the first time you drive a car abroad on the otherside of the road - you get off to a bit of a shaky start but then you get on with it.
Schools - A big point brought up here, you have a disadvantage that you cant go and tyre kick a school before you sign up! There is no real answer to this one apart from asking on here or other boards what people thought of various schools.
Arrival back in the UK - There is , quite frankly, a lot of cr@p spoken about this area. On my return I had two checkflight for two clubs I wanted to hire aircraft from, the max time was 1h 15m, both clubs were quite happy to hire aircraft to me. The '15 hrs dual' mentality is basically perpetuated, as stated before, by instructors who do not the fact that students have taken their money outside the UK to learn. I have heard instructors state that the quality of training is worse in the US but there again I have watched UK trained pilots bounce their aircraft down the runway and commit airspace violations. <img src="rolleyes.gif" border="0">
There are pros and cons to the UK & US but wherever you end up you have a lot of fun!
Julian.