The F8000 isn't particularly good for gaming due to high input lag. Game Mode isn't adept at reducing it; and while PC mode does bring it down to a more acceptable level of 40-50ms compared to Game Mode's 81ms, it has the disadvantage of disabling Smart LED, the picture setting responsible for keeping blacks deep and consistent.
If you liked the look of that LED compared to plasma, you might want to check out Sony's W900A. It should be around the same price or cheaper, but it has a slightly better picture than the Samsung and one of the fastest displays for gaming.
The W900A listed at 3,300 when I was shopping for an HDTV, so I went with the F8000. Naturally after my return window closed the price of the Sony dropped a thousand bleeping dollars. What the fudge...
Now I'm considering an affordable plasma for a second set dedicated to gaming. The VT60 is a little out of my range, unfortunately, but if I can find the ST50 (or if Panasonic reduces the input lag on the ST60) I'll probably pick one up in the next few months.