With my last ISP, someone claimed the entire DHCP subnet block with OpenDNS and turned on High filtering for everybody. OpenDNS refused to turn it off for my IP address saying "Your ISP turned it on".
My ISP said "We have no idea what you're talking about".
So, things were extremely fast, since with OpenDNS, YouTube, FaceBook, MySpace, Vimeo, half of the other sites, etc... were gone.
I assume surfing got a little bit faster when I switched both ISP's and DNS services.
I'll pass on OpenDNS, thank you.
P.S. Google's is 188.8.131.52