Nimbus raises an interesting point.
The US is a BIG place with regional variations in the weather norms. I've flown in California where the weather tends to be friendly and predictable (although you wouldn't wish to get caught near the mountains when the Santa Ana wind blows off the high desert. "I learned about windshear from that."
I've also experienced very unpredictable advection fog and low cloud formation in Cape Cod, where it can all go pear shaped in a matter of minutes.
If we talk about flying in the US, we should perhaps equate the US to the whole of Europe and then try to compare like for like. e.g. learning in California would probably relate to Southern Spain to some extent, New England more like Britain.
Its a good idea for anyone who learns in the US to check out throughly in the UK, as the R/T techniques are quite different, as are some of the customs and practices at uncontrolled fields, e.g. 45 degree downwind standard join, as opposed to an overhead.
Also, carb heat is used less often (in my experience in the USA), whereas I think that most UK pilots would be keener to employ it.
In the US, there can be more teaching of leaning the mixture, often due to operations at higher altitude fields... e.g. at Big Bear City in Southern California, you have to lean on the runway to get full power as you are at 6700' before you start rolling! The difference in take off/go around performance is unbelieveable until you have experienced it.
Final, wing down landing is taught for cross wind approaches as the norm, whereas it is the crab in the UK. I "surprised" one US flight instructor who had never checked out a UK pilot before and we had a good laugh about it over a beer afterwards.
With regard to the intitial point about differences training, it would strike me as a very good idea for a C150 newby to check out with an epxerienced AA5 instructor.
A few months after I passed my PPL, the flying club converted me on to a Cherokee 6 at 70 hours and I was surprised how different it was to a PA28 and more importantly, how easy it was to become comfortable quickly with a few "grey hairs" giving valuable advice from the right hand seat.