We have been in the USA 10 years and are probably staying (kids settled in). It does seem to me that quite a few people commenting have not spent much time in the US!
Healthcare yes, a problem. However if you get it through work as most people do the premium is standardised and not based on your health conditions, same for the Obamacare plans. Ideally I'd rather have neither the NHS nor the US system. The problem here is really if you are between jobs, want to strike out on your own, or your company's offering is poorthere's no alternative choice. The actual care--my experiences have been fairly good now that I know the system and know how to act. I have 2 DC with SN and I do think things here went more smoothly than they would have on the NHS where those services have been cut badly.
Racism--it's a problem everywhere, however i have found that many white Brits really underestimate racism in the UK because it's less visible in much of the country.
Guns--depends where you are. There are entirely different gun cultures in different parts of the country.
ChurchsameI laughed at the idea of being hauled off to church. We are non-Christian (and practising) and this has never happened in the major cities we've lived near! In parts of the Plains states and the South, yes. On the West Coast or urban Northeast, no. The very "churchy" culture is tied to white evangelical Protestantism which is stronger in certain parts of the country. (Nonwhite Christianity has its own subcultures that are different)
The food--a lot of it is very good. Supermarket bread is rubbish but British isn't much better in my opinion. You do have to learn how to shop as the major chains are often mediocre.
Cost of living -- I remember when the USA seemed cheap when I first lived here 20 years ago. Not anymore. Utilities can be pricey, Internet is pricey now (monopolies). Housing of course varies hugely across the country though you tend to get more space for the money.
Education--DC are doing very well. Inclusion for SEN is better done here and the public schools can't exclude children because they don't want to put in the resources or the children "can't cope" (they can write a bad IEP... but they can't refuse them). Schools in my area are all done geographically, no worries about applications. Class sizes are smaller than England though this varies a great deal by place.
Colleges vary widely. Some are very cliquey and trade on name, some are quite generic feeling public universities, some are the big public universities with fraternities and football you see on TV. The cost is the issue, though public universities are not as expensive as you might think and often similar to English fees. The problem is the system for loans for tuition isn't as good.
Holidayas with insurance the big issue is that everything is up to your employer. If you have a generous employer you can have quite a decent set of benefits including holiday time. But there's no guarantee of it. You're at their mercy. So if you're in a field where employers are competing for talent and offering fringe benefits the US will work out great for you. I know people in tech who have free health benefitsthey pay nothing towards the premium and only a minimal deductible--and all sorts of other perks. The US is great for them. But be in the wrong sort of job and you get nothing.
I do like the diversity--the US is so different from place to place, from the scenery to the people to the culture. You can have a totally different sort of life depending on exactly where you are. People are generally friendly. I'll pass on Hershey's chocolate but the children are used to it now (and Europeans frown on Cadburys so I can't be too much of a snob).