MI Friend- You need to remember that you are probably posting in the wrong place for this question, these answers are from people that have made a very happy move to the U.K, but weren't actually born here.
For people born here, there are differences, but that's all they are differences, not necessarily better or worse. For example as someone who was born here, the opportunity to purchase a property that could be a lot more spacious than what you can afford here is a big deal, but only for someone who actually wants to do that. For example, I am tired of having to rent a place in the part of the countryside I grew up in for the equivalent amount of mortgage I could pay on a 2-3 bedroom home to where I am going.
Depending on your partner's upbringing he also might be sick of living in an overcrowded country on top of people all of the time, but then he might just be totally used to a very metropolitan lifestyle and move to similar in the US.
For me there are other "differences" I am interested in, a general attitude is one of them, I have met many Americans who have a really positive attitude to life and "get up and go"/"can do" attitude that some of us Brits just don't and thats a huge novelty for me. I like it when an American who doesn't know you too well actually says "give me a call and I'll show you around" and they mean it. I also like how family orientated americans can be and back to the patriotic thing, I don't understand it myself, but I love how proud Americans (can) be of their country.
The sheer scope of the U.S is another draw, the opportunity to experience so many different areas/landscapes and the value that is in the actual experience of living abroad and providing yourselves as a family and any children the opportunity to work anywhere in the EC as well as the U.S is always a smart move in my book, that said, I also think this can be a double edged sword as you can be constantly weighing up where you might be "better off" and better off doesnt always translate into "happier" and just having the choice can make it difficult to settle in either place as you always know you can go.
I cannot think of any particular freedoms anyone would have to give up though, apart from being able to walk to a lot of places here and not being so dependent on a car! Politically speaking and otherwise, I cannot see any freedom anyone would lose, apart from not being able to vote in the US until you are naturalized.
Can you be a bit more specific about what area youre in what differences your partner might be concerned about?
