I've had a PM from Kitz confirming who it was at Plusnet - he has been there a long time, was heavily involved with the network configuration from way back and really knows his stuff. I had a testing session with him where I was disconnecting/connecting, he was looking at which MSIL I'd connected through and I'd run a TBB speed test looking for the slow x1 result. He was able to accurately predict before I ran each test whether it would be good or bad.