Interesting. I haven't seen one in person so can't comment on sparkliness or dullness. Everyone's tolerance for anti-glare sparkliness seems to be different, and I'm not sure what he means by dullness. There's a 100+ page thread over at Hard Forum about the U2412M which will most likely answer all questions about it:
http://hardforum.com/showthread.php?t=1615513
TFT central does good reviews and will cover what you need to know about image quality, accuracy, responsiveness, contrast, etc.:
http://www.tftcentral.co.uk/reviews/dell_u2412m.htm
I ended up with the ZR2440w because TFT centrals report seemed to be a little more positive than for the Dell, and I found it for $350 on provantage.
I bet the Viewsonic is a great monitor, but didn't research it because 1080p is a deal-killer for me.
http://www.tftcentral.co.uk/reviews/viewsonic_vp2365wb.htm
EDIT:
http://www.overclock.net/t/1225919/yamakasi-catleap-monitor-club
^ Everyone looking for a monitor should be aware of that option. It's a ridiculous deal, though maybe not for you.