Every part of AAISP service is top notch.
When they provided new line and service to a new flat, everything went to schedule and worked flawlessly.
When I started having problems with the line, they diagnosed it and had a BT engineer out to the box in the street asap.
When I upgraded to FTTC, the speed increase was as advertised, and they even tweaked the configuration of the wifi router when I was having a small problem using the wifi on my phone.
Non-filtered, great support for non-technically minded people, loads of tools for geeks.

You might think it's on the expensive side, but it's been worth every penny.