I would say that you should hold on to the NS10's as well. They aren't Genelecs, but they're not supposed to be. The NS10's have been the staple ever since "Thriller" was supposedly mixed with a pair. You'd be hard pressed to find a respectable studio that didn't have a pair for general reference. If you know how to mix on NS10's, you're pretty much set to mix at any facility.
The NS10's aren't great monitors, not even close, but they represent the "everyman speaker". They're a good way to check how your mixes are going to sound when they are blaring from the end-user's boombox.
At our studio, we have a pair of Tannoy Super Red 12" for the dirty work but also pair of the crappiest Philips two-way speakers from the 70's. They're a good method to check how the music sounds in the "real world" where most people don't have the luxury of a high-end room.
