two primaries and no slaves - good or bad?

[Hugh Beaumont]

Hi List,

[I tried to find an answer to this in the archives but was unable to. It is a pretty basic
question and I'm sure it has been convered before - however it was a bit hard to find exact
keywords to search for. Feel free to point me to archived discussions or FAQs. TIA.]

Right now I'm nameserving for about 100 or so domains. I have two nameservers.

ns1 runs as a master 

ns2 runs as a slave to ns1