Having just joined up to the site and found this thread, I can offer a "long term user" insight into the experience of being a Plus Net customer.
Having been with them since the days of dial-up only, going through ISDN Home Highway, Bonded 128k lines, 2Mb ADSL and finally onto 8Mb ADSL Max, I can honestly say that they are the only provider I have come across to offer such transparency into their operations together with a very comprehensive range of standard facilites available to all their account holders.
It is true that they offer Tiscali service on an LLU (Local loop unbundling) basis, but again, this is something that you can opt out of at the touch of a button.
It is also true that they are now owned by BT (something that initially worried me) but to be fair, it would appear that they have retained complete autonomy and if anything, service keeps getting better.
All of their customer facing operations staff work out of their Sheffield Head Office and (up to press) I have never had the disappointment of speaking to someone who just reads from a script - a lot more than can be said for a lot of ISP's.
True again is the fact that Plus Net use traffic shaping systems (Ellacoya switches) to maintain a healthy network experience for all their subscribers, BUT it is also true that they light up new pipes (155Mb segments) on a very regular basis to ensure that there is enough bandwidth for all.
99% of anything you will ever need to do can be achieved online and if not, you will get some sensible help from a knowledgable person on the other end of the phone.
You can subscribe to Service Status emails which keep you informed of any issues that may be coming up or existing. Even proposed maintenance and improvement work is posted so you are kept fully aware of everything going on. They even have webcams in the customer support and development offices so you can see them working 24 hours a day..... as I said earlier, totally transparent.
I know that this sounds like the mad ravings of a Plus Net fan, but it is not without justification.
I personally spend a lot of time working with computers and subsequently come across all sorts of installations, with all sorts of different ISP's.
Believe me when I say that having dealt with a lot of the other "also-rans" and experiencing the unbelievably bad customer service they provide, you could do a lot worse than signing up with Plus Net....... a LOT worse.
Research yourselves a few of the annual ISP awards and you will find the answers you need :)