Its not for me as I have Virgin Media, but my Son is in an area where Sky would have to charge about �17.00 as he is a few miles from town. He had Tiscali who were not very good at �11.00.
He has a BT line and wants to pay between �12.00 to �15.00 a month.
for reliable it makes no difference who you are with, it's not the provider it's the quality of the line coming into the house!
think as it like your gas... you can get gas from several providers, but if you had a huge leak in the pipe coming into your house that stopped the gas working to your house then simply changing providers wouldn't fix the leak.
I have BT line and got PlusNet DSL with free wireless router - no contract, but if I change providers within 12 months I have to pay for the router. �14.99/month for my package which gives me 8G monthly usage. Very pleased, not one problem with my service in 6 months I've been with them.