IMHO the answer is it all depends.
- with three or four or more fast Macs, and assorted other devices sharing the bandwidth and all in heavy internet use, the difference would most definitely be noticeable.
- As Pendragon and the Verizon guy said, even a single computer downloading large files, such as a movie, you would notice the reduced bandwidth.
- With a single computer doing routine internet browsing, email, etc. you might notice some, a few, graphic intensive sites loading a bit more slowly.
As I say it all depends on your needs and to a certain extent your tolerance for delay.
FWIW, my ISP, AT&T, only accepts speed test results from
Speedtest.net. I have found their results to be in line with what I get from
WhatIsMyIP and Speedtest.net has test servers all over the country to choose from.
