After the other survey started to become troublesome (mixing those using FTTC and those who aren't), I've had a go at programming my own on a dedicated web page.
Simple form asks which FTTC ISP you use, your usual downstream and usual upstream speeds. Just select your details from the drop downs. You submit it and it gets logged in a database. You only need to click submit once and the page will tell you if everything entered correctly (or not, if i've broken something).
The results from this database are then read out on the results page. The advantage is it's my own domain so I can adjust it easily or add extra functionality if I'm capable. Please only vote if you're actually using FTTC. If your ISP is missing then reply and i'll add it to the list so you can vote for it. Please only vote if you use FTTC and only vote once.
You can access the survey here