Not really. Some (most?) ISPs have servers in their own networks that can speed up the loading of, for example, YouTube videos. By not using your ISP's DNS servers, you will miss them.

Ironically, the most common fix for slow choppy youtube videos is to swap out your ISP's DNS.

This used to be true, especially with Comcast, but I read a blog post about a year ago stating that in most cases using Comcast's DNS servers is actually faster nowadays.

I closely benchmarked it and they turned out to be right, though 8.8.8.8 had only a little bit more latency. And it makes sense; your ISP will always (theoretically) be able to provide lower latency than Google can when they put the effort into it. Unless Google is your ISP. :)

Google has a tool that will find the fastest DNS server for you, and check for censorship (though IIRC I found that part rather ambiguous). In my case my ISP's was faster by about 30%.

https://code.google.com/p/namebench/

Never had an issue. I've run benchmarks against mine and then google's and didn't see any noticeable difference. Google only seems to offer me what I assume are massive privacy violations for using their service.