I had them for quite a while, 3 years maybe. Personally i wouldn't go back to them, the throttling was really aggressive when i was with them, it was supposedly only in affect during peak hours (i think it was 8am till 6pm) but it seemed to be all the time. I'm not sure but i think i had 20GB a month to play with, as soon as i hit 10GB i'd be on 2Mb, i think the next stage kicked in once you hit 13GB which knocked you down to 1Mb and more than 15GB put you on 0.5Mb!
The service was reliable, i think i only had an outage once and that was due to BT upgrading the exchange/playing with something so was nothing that Plusnet had done themselves
As Evan said they are part of BT now, once that happened things went down hill for me at least. I kept getting threatening emails about using too much bandwidth on and off peak

After a couple of months i had enough and went to Be who i've had no problems with
I'm out of bed and dressed, what more do you want?
I always take life with a grain of salt, ... a slice of lemon, ...and a shot of tequila
I used to have an open mind but my brains kept falling out
One more step to enlightenment ... but which way ?