From what I've heard, the recent PLS displays have been somewhat mediocre, all of the drawbacks of MVA and TN panels with none of the benefits. The only PLS monitor on Newegg right now has some rather terrible reviews.
So everyone suggests a IPS monitor is waaaay better? Jeez now I am mixed again...
Like jaguarskx said, PLS is new. IPS is tried and true - you can't go wrong with it. The only downside is expense, but the catleap fixes that problem (I'm sure you know it's cheap because the stand is wretched and it's basically feature-less - but the panel is great).
I hate to disagree with some other posts here, but I prefer PLS, at least for programming. I have a Samsung S24A850DW (1920x1200) which is on the expensive side, around $450 when I bought a year ago, and it had a electronics problem and had to go back to the shop. I needed a backup so, I bought a mid $200 IPS replacement (1920x1080) to hold me over until I got the A850 back. The IPS have a dirty look to them, kind of a sparkle to the screen when viewing text on a white background. Same reason I had returned the two Dell U2410s I had bought a couple of years, the IPS technology has not changed.
I prefer PLS the screen is much easier to look at, at least while prgoramming. I can't make any statement about gaming on them, other than I am sure the IPS dirty, sparkly look is probably not an issue. The best way I can describe the A850 is it has a look that is similar to TN displays, but a little more vibrant and clean looking. Screen is very uniform, although when I purchased there were some yield problems and I had to return one monitor to get the one I currently have. I can look at the PLS screen a long time, very easy on the eyes compared to IPS, which seems to fatigue my eyes earlier.