I also use a 21" 1600x1200 with a Samsung PVA panel as a second display, the vertical height lines up nicely with a 27" widescreen. It's kinda fascinating to see how the PVA panel, which is like 20 year old tech, has no issues keeping up with a modern IPS display, and even has lower viewing angle shift, no backlight bleed, far better contrast and hence deeper blacks. The only teeny tiny problem is that it's visibly slow, even for a 60 Hz TFT.