Netomnia have offered 10Gb for a while now. They're laying around our area atm, though not in our street yet. If/when they do arrive, we'd be taking the 10Gb service unless it was prohibitively expensive (more than a couple of hundred a month). As ChrisD said, they're an alt-net, and a rapidly expanding one at that - their investment is almost £40m just in my city alone.