My brother stopped by last night to see my week-old 20" iMac and decided he had to have one for himself. To make a long story short, I sold him mine and picked up a new 24" today to replace it. Anyway, I've got them both side-by-side on my desk for the evening, so I thought I'd share some observations of the two displays: Viewing Angle: The 20" does have a slight shift in color saturation while viewing content top-to-bottom. It's not horrible by any means, but the 24" doesn't have this problem at all and also does much better when viewed other than straight on. The 24" definitely wins this category, but I think the 20" is fine for normal, on-axis viewing. Color: The 20" is horribly calibrated out of the box but looks great with a good profile. The 24" looks awesome right away. My perception is that the 20" looks a little more vibrant while the 24" looks a little more saturated. I think I'll call this one a tie since they're both quite striking. Illumination: The 20" is pretty much perfect. It has no detectable variances in brightness and also no significant backlight bleed on an all-black screen. The 24", on the other hand, dims in the corners somewhat and does have a little bit of bleed near the bottom. These problems aren't worrisome to me, but side-by-side, the 20" wins. Bottom Line: I think that both displays are very good and that most people would be happy with either one.