OK, I have the NEC FP2141SB, which according to NEC-Mitsu's own level two techs, is IDENTICAL in every way to the DP2070SB.
I'll attempt to address your list:
Text quality: Good at all resolutions, I'm not a stickler for text quality though, but after using this monitor, I can identify poor text on other monitors much more easily. 9/10
Sharpness/Legibility: Very, very good, but my Hitachi CM771 (.22mm stripe pitch) is actually better in this regard. 9/10
Brightness: SuperBright says it all, this thing is bright beyond usefullness if you want it to be. 10/10
Contrast: Stellar, colors differentiate unbelievably well. 10/10
Convergence: Perfect on all the ones I went through. 10/10
Moire: A problem on my Hitachi, there is no trace of any problems on the NEC. 10/10
Purity: Very good, gets better with use as the "dirty" look in the corners or the vertical lines on the screen go away with degaussing. Not perfect, however. 8/10
Color Rendering: My favorite aspect of it. Colors are much, much better on the NEC than on my Hitachi, which looks bland to me now. 10/10
Geometry: Splendid, NaviSet even makes it easier. Some resolutions, naturally, are tougher to set than others, and geometry is NEVER perfect. Well, maybe LCDs can have perfect geometry

9/10
Refresh Rates: You name it, it'll probably do it. My video card (ATi Radeon 9700 Pro) is actually the bottleneck. Still, 2048x1536 @ 85Hz? More than I'll use. 10/10
Problems: TourGuide, myself, and a guy called Muse all went through the same ordeal. BUY FROM A REPUTABLE DEALER. I think Muse and TourGuide went through two monitors, and I went through three. NEC/Mitsu's customer service is top notch, by the way, so I'd suggest dealing with them before your retailer. I don't remember their particular problems, I think they were geometry related (a problem I never encountered), but my problems were a series of dead phosphors on the screen (black dots) on monitor two, and whacked out vertical linearity on monitor one. Good luck.