Ironically I was in the exact opposite position to you about a month ago!
I was really happy with my BT FTTC 80/20 service and got rock solid 75 down and 19 up on the various speedtesters (inc. TBBx1 and HTTPx6 tests), and good pings (15ms). However I was less happy with BT's price increases and, after working out how much I was spending a year (about £650 after the increase), decided to look for something cheaper and after much contemplation switched to PN.
The PN 80/20 service has so far been really good
off-peak, however during main peak hours speed tests show significant reductions in bandwidth (sometimes down to about 20-ish down) and I've suffered occasional buffering whilst streaming netflix & amazon prime video, which NEVER happened when I was with BT. Then of course there was last weeks PN outage, but let's not dwell on that. Bottom line is I'm saving about £185 on what I would be splashing out if I'd stuck with BT and, as I work shifts so use the broadband mainly offpeak, I'm happy to live with occasional slowness.
I guess the old adage is true... you do get what you pay for - and I'd happily tart myself back to BT after the PN 18 months contract is up..... imho BTs service is clearly superior to PNs in terms of bandwidth / pings and absence of congestion / traffic shaping.
Edited by Psyman (Mon 14-Sep-15 22:56:56)