Until today, my Comcast Cable speed results, as tested on your site, were mostly either in the high 3's or low 4's. Now they are mainly in the mid 2's. Interestingly, other test sites still record my speed in either the high 3's or low 4's. It seems to me that testmy.net may have changed some aspects of its testing procedure(?), thereby producing lower result figures. What is does appear to say, however, is that most bandwidth testing is a VERY inaccurate method of measuring speed. Who knows what is really is?
WBDUTCH