I just moved from BT to Sky. Had had enough of vision. The basic stuff like getting the freeview channels and having a digital recorder are good as is the menu system however the additional stuff like on demand, movie rental especially in HD are terrible if you have a low broadband speed. For example if you want a high def movie you need to first download it to your vision box and then watch it from there i had a speed a little over 3 meg and it took almost 6 hours to download one movie.
Power line adapters are a pain in the @rse. Box would crash almost on a monthly basis. Look closely at the broadband contract for leaving them too, i tried to downgrade my service and was told I would have to pay a charge for this that equated to more than the difference of the rest of my contract period at the higher price.
I may just be bitter about my BT experience but I’d be sticking with sky