The G520 has a maximum resolution of 2048x1536@60Hz. At that resolution it performed admirably, but even at 21" the desktop was too small. Running at lower resolutions results in a more usable image and also much higher refresh rates. 1600x1200 runs at 85Hz without any problems. As I mentioned earlier, I found the image to be a little on the dark side (no Star Wars reference intended) compared to monitors I normally use, but this is probably just a personal thing.
Anyone looking for a good workstation level monitor will be happy with the G520. The sheer weight and size of this screen makes moving it a chore, so I probably wouldn't suggest getting this monitor if you are planning on taking it to lots of LAN parties... unless you really want to impress your fellow gamers with a sexy screen, in which case you'll be very happy with it.
Large screen size
High screen resolutions and refresh rates
USB hub built in
Big and heavy
Auto-Size screen adjust doesn't work well
Rating - 9/10