Hi RMCF,
The SD channels (the majority on Sky currently) look marvellous on our full HD Sony Bravia TV. Could not believe the SD quality when we first got Sky 6 weeks ago, even still we marvel at the picture definition !! Every SD channel is superb including CH4 & BBC2 which could be especially poor on NTL.
Also the Sky + box is a very neat package of tricks, so simple to record, live pause, full programme legend & information, etc, etc. Even after familiarity with some similar features on HDD recorders, Sky + has taken the convenience to another level.
I changed from NTL analogue - definately no going back !!!
Hope this helps.