A rare satisfied customer here ...
(note, I didn't say "happy")
We moved in 10 years ago, when Telewest were cable providers. Since they offered an all-in-one phone,TV and dial-up (!) package, we joined. The only criteria then was "anybody but BT". We have stayed with them, and taken advantage of various promotions to get 6 months free broadband (in 2004), a free upgrade to V+ (2008) and this year a free upgrade to TiVo and the basic 30MBs package (which needed a new modem).
In that time, we've had 1 outage on the broadband. I think they had lost the pairing of the modem with the network, as I called up, and had to quote the modem MAC address. Fixed 5 minutes later.
Speed is pretty much as advertised. Never experienced issues with traffic shaping - maybe because I just set downloads running on my 24/7 server. When they're there, they're there. My only grumble is the slightly od mix of channels on the "basic" TV package. But since we're not sports fans, and our son is way past the cartoon network stage, we're not missing much - it's be nice to have Discovery HD for example. But we manage without.
Customer service on the whole is acceptable - yes you can have some problems with the offshore guys, but if things get too bad, hang up, redial, and select the "I'm leaving you option" - you'll get a UK person, who will knock a few quid off, or give you a discount on a new service.
When I became a homeworker, 3 years ago, I got lumbered with a BT Openreach Broadband connection. The saga of getting it installed, and activated, and the billing sorted was WORSE than I feared. Since I was already expecting a series of missed appointments, incomplete work, and messed up billing, they really went some to go under a bar already set at -10.
Every so often, just for fun, I run a speed test on both connections. Here's todays results:
BT: Ping 39ms DL: 4.87Mb/s UL: 0.72 MBs
VM: Ping 20ms DL: 17.91 Mb/s UL: 1.98 MBs
and that's real. I can download a 1 hour programme in 3 minutes.
Compare and contrast with the in-laws who live a mile away, and have been with every combination of non-Virgin there is ... I stopped counting at the 5th incident they had where they lost internet connectivity in 3 months. Each time they had a round robin of calls between BT and the ISP.
I know VM are a premium service. But that premium saves a lot of hassle should things go wrong.