I've been with Sky for phone and broadband for a number of years and have never had any problems. It's worth checking to see if you local exchange is LLU (local loop unbundling) as that means Sky are the actual supplier of the broadband service. This will give you a good chance of achieving the best broadband speed. You might find a lot more help at http://www.skyuser.co.uk/forum/ which is an independent Sky User forum with very helpful users.
Sony Xperia Z5 review: Hands-on with the phone which the Z3+ should have been