Always nice to read someone's experience. Thanks, VikashLurker.
The US is so huge and diverse, even the fringe can be generalised.
Other than the national fast food chains, food varies greatly from region to region, in my experience. I'm off to East Texas this week, for a month or two. It's not the arid Texas you know from the movies; it's green and full of trees and lakes. One of the nicest restaurants just outside town is on a wine estate owned and run by a South African. Great food. But we've also eaten at a downtown restaurant where is simple barely passable meat dish was $85. So, it depends. What there is plenty of is choice.
The local and regional grocery chains have an astonishingly great selection, all immaculately displayed. Every apple is polished and labelled. Quality on most items is significantly better than we get in SA - it seems the best of our local is exported and SA consumers sit with 2nd and 3rd grade stuff. For home cooking, the taste is also generally richer and better than our local foods.
Where you pay higher than locally is for anything that involves personal services done by live bodies, like sit-down restaurants. Our local restaurants are astonishingly cheap and offer very good value, especially on meat.
People-wise the Americans are on the whole extremely polite and friendly, almost disarmingly so. I sometimes wish for a bit more British reserve. 90% of them are people without guile. Seriously.
The entertainment industry and media do us no service in their portrayals of America. All we see and read about and watch in our entertainments is Americans being bad, corrupt, immoral. So when we finally get there everything looks exactly as it does in the movies - the same cars and roads and cityscapes and suburbia, and the people speak with the same accents - and so we assume that's how they are. But it's not true. That's a fantasy world. It's not how the overwhelming majority of Americans are, especially not those working and bringing up families. They are a very decent, capable, and friendly and extremely generous people.
Small anecdote: In the same neighbourhood as my daughter lives a good friend who married an Indian (from India) about 5 years ago. When I spoke to him just over a year ago about his experience as a non-pale-male in America he said it was fantastic, not even a whiff of a hint of anything funny/racist from anyone, and far, far better than anything he has ever experienced in India or Britain.
If you can adjust to a rather different culture, and forgo the power and pulse of Africa, then you will find America an amazing place, where you can still achieve whatever you set out to do and tackle with hard work.
Good luck in your decision.