22" LCDs are for the most part all interchangable. I don't think I've seen any 22" widescreen that didn't use a TN-type panel. TN is great for gamers, I guess, since it has fast refresh, but the viewing angles are pretty crappy and many of them are 6-bit from what I've seen.
Most 24" panels seem to use some variant of PVA technology, which has better color rendition, more contrast (blacker blacks) and much better viewing angles.
Some info on different LCD panel types:
http://www.hardforum.com/showthread.php?t=1039222