don't be fooled into thinking that it is similar to the VP930 in anything other than design really. The VP920 uses a very different panel to the VP930. On the one hand, the VP920 uses a 4ms G2G TN Film panel. This does offer good gaming performance thanks to its fast response time and a heavy dose of overdrive has been used to boost grey to grey transitions. However, the TN Film technology suffers from restrictive viewing angles, especially vertically, and also movie noise can be quite apparent, especially on panels like this which use overdrive technology. The VP920 is very much a gamers screen....
On the other hand the VP930 is arguably the best all round screen in the market right now, offering excellent performance thanks to it's P-MVA panel technology. It uses an 8ms panel from AU Optronics which still offers good responsiveness, but offers wide viewing angles, smoother movie playback and a deeper black depth than TN Film can offer. This is why the price is higher.
I think you would need to decide what you want to use the screen for really....