Without going into a massive amount of detail, since September I've had a extremely poor service from Virgin-meda so anyone considering an ISP change please be warned...
1 Frequent periods of no Internet, when I contact support I'm told I have a signal to noise problem which will be cured in 4 days during which time I've got either no or a very intermittent connection it's got so bad now I've almost lost the will to try to access the net.
After the fix time has been reached, I get a phone call saying We've fixed it, within an hour or less I find out that they haven't, another call takes me back to where I was in the beginning
See 1 above.
So its up to you.
The problem for me is I've still got until next October before my contract end