Guys,
As of 5.3.7R1, the local /etc/netgroup file is cached. We had a big bottleneck that was eliminated in this release. When you have a netgroup file that's almost 750K and the filer had to parse it for each mount, CPU hit 100% in no time.
This doesn't help caching the NIS netgroup's, but it's a start. Still can't export rw or root to netgroups. :(
/Brian/