Performance is not always that good
Even in France, where I live, performance is rather frequently lacking. I have a good line, rated at up to 20 mbps. At any time of day, I get 8 mbps minimum. I have a full contract, TV, phone and Internet access, no capping (as was remarked earlier).
Internet access is by far the most reliable. I frequently have the same IP for weeks at a time (it only changes when the line goes down or I turn off the box).
The phone is a bit more dodgy. Sometimes I hear of people who phoned me but I never got the call. Other times I want to phone someone and I get an incomprehensible "this number does not exist" error. Try again and it works. The number is recorded in the phone, so it's not a typing error.
Of the lot, TV is actually the worst performer. It regularly stutters, there is frame drop, sometimes the connection is entirely lost for a few seconds. When it works, it works fine, but it fails so often that when we can watch a whole show without any issue it's more of a surprise than anything else.
In such conditions, Internet TV has been relegated to the backup solution when satellite reception quality is too dodgy. And if it starts acting up at that point, well it's either pop in a DVD or go read a book.
Frankly, I feel that the Internet is not the best medium for this kind of usage. Either that, or there's serious need of improving backbone bandwidth capacity, even in France.
I shudder to think of the situation in the UK. I really don't see how they can offer Internet TV with any hope of reliability from all the capping and bandwidth issues I read here and there.
But Internet access itself ? Fine and dandy.
Then again, I'm fluent in both French and English, so the Web is vast for me.