I'd definitely go for the Apple 27" Cinema Display. After using a 27" iMac there's no going back to a smaller screen.

It's faster compared to Aperture 2 but much much slower than Lightroom 3 (iMac 27" Core i7).

Reading the comments was almost as nice as reading the piece above them. One of the few sites where this is simply how things are. I'm a Nikon convert from Canon thanks to the D700. I was worried about the dials and "lo" message as well. Turns put the dials could be reversed and I switch to manual to get rid of the foolish "lo" caption. Oh and the 14-24 is definitively worth it. Got rid of my 16-35, 24-70 and 70-200 IS (all f/2.8). Switched back to primes for the other focal lengths, but still waiting on a new AF-S 35mm f/1.4G for FX.