Nothing inherently wrong with using whichever DNS you'd like, but a geographically closer one would be better, like say 196.25.1.1 (SAIX).
E.g.
I'm pinging 8.8.8.8 at 200ms. This means that if I go to any website, there would be an additional 200ms for each resource which requires a DNS lookup, and thats only for the IP lookup, not the connection to said resource.
However, using SAIX's, that would only require an additional 4ms (my ping to there) for the lookup.
So suppose
www.example.com has links to pics on
www.other.com and
www.another.com.
www.example.com -> +200ms
www.other.com -> +200ms
www.another.com -> +200ms
for altogether 600ms,
just for the ip lookups (okay things can be done concurrently to minimise this number, but the point still stands), whereas SAIX would take altogether 12ms.