If an isp's customer isn't getting the service they should be getting, they are obviously going to have a moan about their isp.
This is where these review lists fall down, as many customers may be receiving a great service, but don't shout about it.
I've been with Titan for 22 Months now (entanet based supply), and can honestly say that I have received a good service during all the time I have been with them. Any enquiries I have had have been dealt with promptly and helpfully. The speeds have varied somewhat over the 22 months, hovering usually around the 6Meg zone but have never dropped below 3Meg.
There have been no outages, and I've never experienced any throttling, blocking, etc. ( I use the internet regularly (i.e. every day for a number of hours) and often download quite a lot of gigs worth of files.
I'm intend to stay with Titan as I am entirely happy with their service.