My 24" seems ordinary to me after a couple years of use. However, I'm in no hurry to replace as I probably cannot improve on the image quality.
Looking at 30" at the store, it borders on being too big. But, I would get used to it. I seriously wonder if that isn't close to maximum, though (at my desktop viewing distances).
If I do switch to a "big" LCD, I know I can't take the low picture quality and limited view angles of the 6 bit ones. They would not work well in a "big" screen because the contrast would change merely looking left to right at desktop distances (I can already see that in the 24" LCD HDTV/monitor we own). I desire excellent color and wide view angles (needed to maintain the color fidelity as one looks around the screen) at a "reasonable" (not cheap) price.
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ATI Crossfire Sapphire 2x HD5870 - Eyefinity 5760x1200 24", 1xDell-U2410 H-IPS + 2xHP-ZR24w S-IPS, Phenom II X6 1100T@4.0GHz w/Swiftech Water Cooling, 16GB GSKILL PC3 1866@1333, ASUS Sabertooth 990FX, WDigital + 3x Seagate + Hitachi + 2x WD Ext = 10.0TB, Sony DVD, OCZ ZX 850W PSU, CoolerMaster HAF922, TM Warthog HOTAS, TM T-Flight Stick X, TM Cougar+FSSB & CH Pedals, Saitek X52 Pro & Pro Combat Pedals, TrackIR5 w/TC Pro, Windows 7 HP 64b