I havent had a problem with PlusNet to date and i have been with them a year now.
Ok they have limited their P2P usage but i am still getting up to 13GB peak P2P usage per month for 21.99 which i find acceptable.
There was a problem with answering questions on the site in that sometimes it took a few days, but this seems to be turning around. My last query was answered about 6 hours after i placed it.
Overall i am very staisfied with what they provide and hopefuully my exchange will be upgraded to let me get the most of my up to 8mb package.