I thought I would throw my tuppence worth into the mix. I have been with o2 for 8months now, and I had been finding them bearable, unlike alot of the reveiws I did find there customer suport pretty good, most of the time. I am quite a heavy downloader and told them this before I signed up, and was promised there would be no problems in the future regarding this matter, as it is an unlimited package I am on. What a lie that turned out to be, four months ago I received an email, informing me I was a heavy downloader and to keep an eye on it, and they were going to be MONITORING me, I pretty much ignored this, then 3 weeks ago I received a very nasty phone call from customer services. I was told I had downloaded 92.4 gb in the previous month, and this was TEN times the norm. They then went on to say that if I did not greatly reduce my downloading and change my habits I would be cut off. Yes I do use p2p a fair bit, but only from 2am till 8 am as this is the only time I get a good speed from them. I was told this didn't matter in the slightest. Also a month after I joined they began traffic shaping, which was ment to be from 6pm to 9pm, this is a total lie, as my speed dose not pick up till bang on 2am. I asked them if they were throttling my conection and was told no, but I am 99% sure they are.
On a positive note I have had hardly any disconections, and speed is bearable just, but not even half the 8meg promised. If I had the pc running p2p 24/7 I could see there point, but only running p2p 6 hours a day and being told I am using to much bandwidth is just truly unaccepable. They are going to call me in next few weeks to tell me if I am getting binned, so watch this space.

Don't bother with O2 if you plan running p2p any length of time, or if you plan alot of other downloading . Also it is truly impossible to do anything but surf in the formentioned "peak times".

I would deffinatley NOT recommend O2 unlimited to anyone as it ain't " unlimited" downloads, infact not even close, you are pre-warned fellow p2p pepole !!!