We are connecting to our
server using AFP.
Is it worth it to go to NFS? Is it going to be
faster?
Almost certainly not, to both questions.
Although I don't have citations for any rigorous tests, my experience (and others') is that the NFS client is rather slow. (Here's a
recent post on the subject.)
More to the point, NFS is far less secure than AFP (there's no user/password authentication like there is with AFP). Depending on the applications you use, it may be less robust. Also, the feature set doesn't completely overlap with AFP. With AFP home directories, for example, the directory is created automatically by the server the first time the user logs in; with NFS it's not. On the flip side, NFS allows you to use Fast User Switching with multiple simultaneous accounts from the same client, which AFP does not. I'm assuming that the latter isn't really a feature that you particularly care about; it's typically not a big deal (except in some lab environments).
The main reason to switch to NFS would be if you have UNIX or Linux clients where you'd like to use network home directories. If that's the case, it would probably make more sense to put the home directories on a UNIX or Linux server that provides NFS.
David Walton