I've got a pair of 2001FP on a single video card. With the resolution at 1600x1200, there is very little difference, but you have to be careful on the analog side. You need to use a good quality, well-shielded cable, route it away from power lines, and adjust the monitor properly. The 1600x1200 is very information dense, and very vulnerable to interference -- and if you don't fine-tune the monitor, it can't pixel-up right. I suppose if your video card doesn't put out a strong analog signal, you could be in for trouble.

With it adjusted, I can't tell which is on the DVI and which is on the analog. There is quite clearly a color difference -- one is bluer in temperature -- but I couldn't tell you which is which.