I've had my Crossover since Monday and I really like it so far. It seems to be built really well and the height is perfect, because it just fits under my hutch. Color and clarity is awesome. My eyesight isn't great (probably from staring at a monitor for 8+ hours a day), so I increased the Windows text size by 25% and I zoomed in the forums 1 notch in Firefox. Took me a few hours to get used to the hugeness and resolution (coming from a 22" 1680x1050 monitor).
Diablo 3 looks great, but it's still a 60hz monitor (which is all I've had in the past), so you might notice a little "slowness." I only really notice it when items are on the ground and I try to read their names while moving. It could just be D3. My videocard (6950) is definitely working harder and spinning up the fan, but I still hit ~85FPS constantly in D3 with everything maxed.
Overall, I think getting one of these monitors is a great buy for most people. If you have an older videocard/CPU and game a lot, or you're just very sensitive to monitor response times, it may not be for you. Otherwise, go get one.