I'm with you Overtaxed, which is why I'm 90% sure I'll go with the 19" and 467M on my order. There's way more tires to choose from, and it makes more sense for me up here in the North. I would get myself an 18" Winter package to complement (Winter tires are the law here in Quebec from Dec to March).
I get that the 20" look great and they do. But we have shitty roads and shitty conditions here, so to me, it just doesn't add up. Then again, I may have been spoiled by my previous SUV, an Xterra... But now that I can afford something nice, I'm still inclined to get an SUV/SAV that performs decently in rough terrain (which our roads are) and diesel is a must, but I can pass on the 20" slicks.
My two cents.