I hesitate to enter this one but I shall simply relate my experience.
I have now had two students who (separately) started in the USA at schools I had not heard of. Having completed around 30hrs each (roughly) they returned to blighty for one reason or another.
Both were terrible considering the hours they had done. The real basics of lookout scans, coordination and flying by reference to attitude were absent. What was present was a very relaxed attitude to walkrounds and use of radio.
Both thought I was being Boyo the Bastard when they flew with me as I was so 'picky'. In essence I would evaluate their 30hrs US as 4 hrs useful. The bad habits and attitudes took ages to kill off.
That is my experience. It is bound to be atypical. I draw no conclusions of a general nature. I am not having a go at anyone. I relate merely my experience in this area.
Happy and safe flying,
WWW