I have the same problem on fios. For the last few weeks YouTube has been particularly slow. Buffers a few seconds and then hangs for a bit.

Edit: a bunch of people complaining on a google group thread about the same thing: https://productforums.google.com/forum/m/?fromgroups#!topic/...

I can't tell if this is placebo or not, but my YouTube was loading extremely slowly pre-fix (on Comcast) and now is zipping along quickly.

Another anecdotal "yes" seems to be working much faster for me. Versus skipping, slow load times, random freezes, and, impossible to play any youtubes in HD quality at all. Now, I can stream them. I've had many friends around me complaining about YouTube quality as of late, so interesting thread/discussion and quick-fixes.