Reasons not to use a UK host...
1) Price: they generally charge at least double per Gig of transfer.
2) Legality: they don't like the majority of hardcore which falls into a grey area of UK law and varies from host to host.
3) Specification: they are generally not set up to cope with large amounts of traffic unless you are willing to spend a fortune.
4) Tech support: I've dealt with almost all the popular UK hosting companies and the only one with decent tech support is NTT Verio, basically because you are transferred over the Atlantic to their American call centre.
5) Billing: they generally request 12 months payment in advance.
I actually phoned a well known UK host last month for tech support (true story) and they denied that the site was hosted by them. I told them to check whois and they would see the nameservers. Eventually I got transferred to the "Tech Support Team Leader" who informed me that the site was actually hosted by "Network Solutions".
So if the Tech Support Team Leader has no idea that Network Solutions is in fact a domain registrar and doesn't know that NS1: & NS2 = his company, then how the hell are they gonna sort out a problem that I can't handle myself? I gave the poor guy a few tips on how to find and read whois records, and I'm a bloody designer, not a techie.
If you phone a UK host and ask what content they consider legal for them to host... they will just give you the standard answer which is "
As long as it is legal under UK law." which tells me nothing, because I'm not honestly sure where the law stands in the UK.
If you ever get listed on The Hun for example, you'll be wanting a host that is robust enough to deal with a real battering, and to be honest
www.colo-cation.com is set up specifically to deal with adult traffic and the server stress that it can sometimes bring.
You gotta use the right tool for the job.
I would recommend North Amercian hosts every time.
As for the issue of communication across the Atlantic... there is ICQ and support tickets etc. But I'd rather deal with American tech support and get through to a person who can actually do things to solve any problems, rather than a British person who is just there just to answer the phones and filter calls to delay you and keep the workload down for probably the same number of real tech support staff as you'd get with an American firm.
But if getting a phone answered and shouting at a moron makes you feel better, then knock yourself out.
I actually phoned Blue Gravity once, they answered the phone and sorted out my problem. And it cost me LESS to phone them than it cost me to endlessly phone a British host that was always going down.