Having noticed terrible evening speeds, my previous ISPs accepted the "no BT fault" returned back from BT, with the need for an engineer visit and possible charge (plus the engineer would be a day visit when there wasnt a problem!)
After joining AAISP, I mentioned this problem, and within a week they suggested a problem and got BT on the case, who accepted the issue and did the "lift and shift". My evening speeds have gone from under 1Mbps to 5 - 6

I now seem to be using my allowance on speedtests as seeing is believing!!
Well Done AAISP