Unlocked USA Model shipped to the UK

I'm looking in to pre-ordering the unlocked model directly off of HTC's USA website and am wondering if anyone on here would be kind enough to give me their two cents on whether or not they think it would be possible for me to do this and still be able to use the phone without any complications. I can see that the frequencies used by American service providers are exactly the same as the ones used over this side of the pond but am concerned there might be unforseen problems. I personally have no use for 4G speeds so I tend to stick to cheaper 3G packages with inclusive minutes and texts. I can see that the A9 is a GSM/HSPA/LTE phone but am wondering if anyone has any past experience with importing phones like this one which on paper sound like they should be compatible; if so I'd be interested in hearing your opinion on the matter.

Thanks for reading and I look forward to any responses!