The technical difference is the VX is a TN-Film LCD (like all the garden variety LCD's). The VP the a Overdrive CVA LCD (The really cool ones)
here are the differences:
1. Colour - The VP930 has 8bit colour pixels (24bit colour). The VX924 ( to be replaced by the VX922 btw) has 6bit colour pixels (emulated 24bit colour). personally I would like to see the other 97% of the colour spectrum.
2. Response time - rule no1 never look at the "lowest" response time stats. Always read what the reviewers say. The VP930 has a "higher" response time, but has less to no ghosting at all.
3. Viewing angle - again, never believe the stats, read what the reviewers say. The VX series panels has a much smaller viewing angle and is more prone to colour changes with the angle. The VP930 wil only change in brightness.
Bottom line, if you can afford the VP930, get it, you wont be disappointed.
The VX924 is not better for gaming, it's only cheaper.
I put the VX924 and VP930 on a single PC with a cloned image on dual DVI to compare, The VX924 still ghosts very dark and red patches, the VP930 does it much less.