... A number of people frown upon iMac displays. Surely there are "better" but I'm quite satisfied with mine, and the printed results are fine.
+1
Mine is iMac 27, late 2012, profiled with a Colormunki Display. I usually do not even bother with soft proofing, as prints come out pretty close to the screen anyway. When I did try, differences between original and soft-proofed were so small that you can mimic them just by slightly varying the position of the printout to the light source, for instance.
Until the other day...
I was about to print a fairly saturated patch of red, against a dark background and dark, ink-blue sky, and I decided to check softproofing. And, ahmmm, it did show a pretty significant difference, but only in that red patch. It was more organgy-red than I would like. That's where the gamut warning was as well. But then again, I know that gamut warnings are not precise (i.e., it shows there will be a problem, but not exactly how significant the problem is), and I know (or I thought so) soft proofing is not that terribly precise either, so I decided to go ahead and print it anyway. And guess what? The printout looked exactly as the soft proofing! In other words, it is a testament to both the importance of soft proofing and accuracy of iMac displays.