Aperture 3 was just too much for my 1-year old 13" MBP so I got the new base model 21.5" iMac. I might miss the 24" monitor but being able to use the 4GB of RAM from the MBP for a total of 8GB ought to make up for those lost couple of inches. I'm really looking forward to having a discrete graphics card. This is my first desktop since 2002! Now with an iPad I just can't justify the compromise of power for portability anymore. I hope Apple will give the 13" MBP a real graphics card next refresh to make it an actual desktop-replacement machine like the 15 & 17's. Oh well, I already made the switch and can't wait to see the difference in performance!