NS-10's are the monitors everyone loves to hate... You can find a gazillion people bitching about them (no bottom, "honky", exaggerated mids, etc.), but those same gazillion all have 'em. Not saying they're bad, just probably wouldn't be my first choice for an upgrade. Needless to say, there's a ton of hits that have been mixed on 'em, so I guess that says something. Look around, there's lots of options out there - all depending on how much $$$ you want to part with.
Most importantly, you should listen to monitors before you buy anything - don't base your purchase solely on the opinions of the people on a BBS or newsgroup.
Bill