For what it's worth, the difference between TN (Twisted Nematic) monitors and S-PVA (Super-Patterned Vertical Alignment) or IPS (In-Plane Switching) monitors is in the number of colour bits that they are able to handle. NT are 6 bit monitors, meaning that they can display 6 bits of each of the three RGB colours, for a total of 18 bits, or 2^18 = 262,000 colours. The S-PVA and IPS monitors can handle 8 bits per each RGB colour, or 2^24 = 16.7 million colours. The newer Eizo monitors even have 10 bit colour capability, but they are not cheap. The TN monitors use "dithering" to extrapolate additional colours and usually advertise that they can display 16.2 million colours. The TN monitors usually have much faster response times which is good for gaming. The S-PVA (and the more professional IPS) monitors have slower response times, but as long as the response is less than 33 ms (for 30 frames per second), that it all that is required for video editing. Most modern PVA-type monitors seem to have typical response times anywhere from 8 ms to about 16 ms, although you have to read several reviews on any one model to determine how the response time is measured. Different manufacturers and different testers have their own creative way of testing and describing response times.
Most of this information comes from web sites such as this one: http://www.digital-cameras-help.com/photography/articles/s-pva-panel-lcd-monitors-for-photography/
I would suggest to do a bit of research to determine what is the most suitable type for your work. I have two computers, one with a single TN monitor which I use for work and Internet activity, and another, more modern and faster computer with two S-PVA monitors for video editing. My monitors are 19" 4:3 types and didn't cost too much. Whenever the NextGen product comes out, I may go for a larger, wide angle (16:9) monitor, such as a 24" which has the same screen height as my present 19" 4:3 monitors. I plan to stay with the S-PVA type (such as the Samsung 245T) because I like the colours that are displayed by these monitors compared to my cheap ProVIEW TN monitor.