The u2412 does have a slightly larger bezel but it is still manageable. The biggest factor between the two is the resolution height of 1080 vs the height of 1200 pixels between the 23" and the 24" monitor.
The things that need to be factored in before making the purchase:
The resolution difference is about 9% more per screen with the 24", that's 27% more screen real-estate in eyefinity.
The price difference between the
23" and
24" is about 69% more per screen.
3 x 23" for $623.70
3 x 24" for $897.00
Another note:
The contrast ratio looks better on the u2412
Here are the reviews (not written by me):
23 vs
24
Hope this helps.