The DC location doesn't matter that much if you are using CDN. But most customers are not aware of that and not sure how to use a CDN. So it's better you have multiple DC's and provide them a test IP so they can test the latency.
USA location is always my first choice and it attracted me or affect to my decision when buying a hosting plan because all of my sites are targeting US audience. I think US server location will be better than EU location.
But since used CDN I didn't care more about this factor, just need my hosting server is really fast enough for all locations in an allowed condition.