I got FTTC broadband a few weeks ago and I've been getting slow speeds, often about 5Mbit/s down. The speed estimator said 30Mbit/s. I discussed this in more detail here on the FTTC section.
Here is my SpeedTest.net results' graph:
As you can see, download speed is very mixed and almost never very good, while the upload speed (estimator said 7Mbit/s) is generally very good with a few hiccups. I've talked to my ISP, Goscomb, and they can't find any problems, nor can the wholesale suppliers Enta and BT. The next step is for a BT engineer to visit my home, which will set me back about £120 if they don't find anything wrong.
What are the chances of them finding anything? What success rate (by which I mean a problem was found and the End User wasn't charged) have people had with engineer visits, with any kind of connection? Can any estimate be made for my chances?