The issue is overrated. I'm 5'3, with proportionally shorter legs, and I used 170mm cranks for years (including a 10-year period in which I was car free) with absolutely no complaints. My Bike Friday came with 165mm cranks, and I can't say that I've really noticed any difference in pedaling. Which is kind of interesting, since the bike being custom made means that I have noticed improvements in *all kinds* of other areas.

So I fall into the "overrated" camp as well.

(Alternatively, most people may be using cranks that are too short; it doesn't intuitively make sense that someone 6'2 would be as happy with 170mm cranks I used to use as I was - but 185mm cranks would likely hit the ground. So perhaps 170mm was settled upon as the longest length that wouldn't cause ground strike issues for most people?)