I've been visiting the USA since the early 80s, both staying with friends in NYC and upstate New York, and also travelling all over on mega road trips. Basically hiring a car and then taking off, seeing wide open spaces like you can't believe, huge cities, tiny small towns.
I've driven Route 66 twice from Chicago to LA. So far I've spent time in around 20 states. What I found wherever I went was great openness, hospitality, friendly curiosity and courtesy. Even in places like Manhattan, Chicago, Las Vegas, San Francisco, where you think they'd be sick of tourists. What I also found was a general lack of knowledge of the wider world, other countries, and of course belief that the US is the best country ever.
There was a time when I would have loved to have moved there, probably the east coast, Boston perhaps, but that time has passed. Did it change me? Probably.
Even with 44 years of travel there and having driven all over the country and stayed in places way off the tourist map, I would say I wouldn't presume to know the place or the people. It's so much bigger than we can imagine in tiny wee UK.