To start with, your link did not work.

Try the bandwidth tweak like this -

Use a system without the tweak. Access your email account.
Use stop watch and note down the time take from entering
your password to opening of your account.

Now, apply the tweak and measure the time again. You will know
the difference.

It may not improve in file downloading, but it certainly gives improvement
in accessing encripted pages like those in email accounts. Improvement
can also be found if the site contains many icons or image files.