At the time of writing I've been a client of AAISP for 9 months - they have repeatedly delivered service that is exemplary.
During this time I've asked for assistance on two occasions, both times there was no issue there end, and both times they helped promptly and completely. That's unheard of. Prompt help is seldom complete, and complete help is (in my experience for anything non-trivial) usually days or weeks.
Neither of these issues are trivial. One was even after hours (on a Saturday night) - they were highly technical issues requiring a significant understanding. The first involved TOS markers and the other an IPv6 routing issue. This wasn't just 'reset your router' advice from someone reading a script in a call center, it was serious technical assitance around issues that were not of their making.
Both times the communication was aided by using their IRC channel (accessed via a web client from their website)
To them, I'm a base level client, nothing special. Getting this level of assistance out of much larger providers I deal with on a professional level isn't as easy.
AA are shockingly good. There is just no comparison. At all.
Their product represents good value for money, fair access for a fair price, but with superb service and accessible technical knowledge to back it up!
AAISP must surely be the Gold Standard in IAP service and product. I've never dealt with any one better at home or corporate level.