Its OK, but having to go through a BT line there can be problems because, if you have a fault, Sky will say its BTs fault and BT will say its Sky's fault, so it can sometimes take a long time to get it fixed.
I just signed up for an attractive sky deal- and then a week after I signed up I got a letter saying their prices would be going up by �3 a month with immediate effect. WHata con. I'm tempted to send it all back but I've just shelved out for installation costs