I think
http://www.dslreports.com/ has more accuracy and it has nice tools for tweaking your pc.
anyway, my ISP didnt change my speed yet, I've just called them and they said that 15 days is the time they will take to do that, and if Im thinking about take other measures, please read your contract, (small letters of course) and it says that they can take an average time of 15 days for any change (it means 0 - 30 days)!!!
so, I took my chair and wait