Higher speeds are completely useless since Comcrap throttles everything and anything that takes bandwidth to begin with.
Sure, you'll be able to get your email attachment in 1.2 seconds instead of 2.7 seconds - but good luck downloading any video files.
I am starting to hate Comcast more and more these days.. it used to be a passive "they suck" - which is now turning into "why the hell am I not in Fios territory?!?".