Reply to Organizing a massive library

When I got back into mobile DJing I was using a simple methodology to manage my music library, I am on Mac and currently use Traktor.

Subscribe to iTunes Match
Import into iTunes, tag
If there was music that was not worth keeping local, delete local copy and keep in the cloud
Sync Traktor to my entire local library

This was fine till I reached a 25,000 song limit which I am now about to exceed. So I need a new methodology.

I am also concerned that as my library grows iTunes might start to choke and not be useful.

What do you do with your very large libraries?