Yo tengo la misma duda, estoy entre el VX924 y el VP191b ambos de ViewSonic. Estaba casi decidido por el primero, pero acabo de leer un par de comparativas en Tomshardware y creo que me voy a decantar por el segundo, el VP191.
En esta comparativa explican muy bien como consiguen la velocidad de refresco y verás que no todo es oro lo que reluce … principalmente los colores cuando reproduce video son bastante mediocres según dicen...
http://www7.graphics.tomshardware.com/display/20050602/index.html
_Conclusion
The VX924 is a good monitor for gaming: it's fast, but not very accurate. With a latency specification of 4 ms, that's what you'd expect. Its static qualities are just as excellent, with a well-controlled level of brightness and very deep blacks. But video noise will be a real problem for anyone who uses their PC for moving images - in other words, the majority of users.
The bottom line is that the VP191b/s is a much more multidisciplinary solution, mostly since the gain in latency performance with the VX924 is debatable, as we've seen. The announced 4 ms is more a construct of the measurement method used than it is a true measurement of performance, because it doesn't take accuracy into account.
The VX924 seems to trade off its aggressive use of Overdrive against mediocre performance with movies. That's true for this model anyway, though it's too early to generalize. We're waiting for more monitors based on this technology so that we can compare._
En esta otra comparativa hablan del VP191b
http://graphics.tomshardware.com/display/20050526/index.html