Personally, I dont like the idea of the nagios machine, initiating a connection to another box, asking it to perform a check, and then have to retrieve and display the results. That is far to much work, when you have over 1000 service checks running every 5 minutes.
Using nsca, you have the remote host, making it's own checks, making a connection to the Nagios machine, passing the results to nagios, and nagios simply displays those results. It is far easier for the nagios machine to handle passive checks(results from nsca) than to perform active checks(nrpe initiated).
I'd suggest to ditch nrpe and go with nsca.
Edited Sun Apr 17 2005, 05:45PM ]