In our stable:
152.5 on the ICE, because that was their short crank factory option.
155 on the SMGT, because 170mm was clearly too long.
155 on the Baron, because it was proven to work on the SMGT.
160 on the Discovery and the Brompton, which is available cheaply from Spa (155mm cranks are now expensive unobtanium) and seems to work well.
165 on the Reasonably Priced Mountain Bicycle, because that's the shortest XT cranksets come in.
I find that 170mm is Too Long - feels like my legs are flapping about, rather than working efficiently. (I'm sure many cyclists, particularly women, have never used anything else and think that's what cycling is supposed to feel like. I'm also sure that many cyclists, particularly tall men, haven't a clue what I'm talking about.)
152.5 is basically indistinguishable from 155, and seems a good fit for barakta.
I've ridden a bike with 140mm cranks, those felt silly. (But on the gripping hand, I could ride it without trouble in a way that I wouldn't be able to with 180mm.)
Everything in between seems to fit me well enough, with the usual preference towards shorter cranks for spinnier riding. I'm sure I'd be fine with 160mm cranks on everything.