That depends on how tuned into the bike you are, I use shorter cracks as I have slight hip impingement and the shorter crank gives me more room over the top of the stroke.
How tall are you?
I am 5'7 and the shorter cranks suit me, I am even experimenting with 150mm on the turbo bike.
My drive-side crank is 5mm shorter than the other, it was the only one I had available at the time. I don't notice any difference. Having said that it probably compensates for the drive-side pedal being further away from the centre of the bike because of the chainring.ok. I also have a leg length discrepancy, so maybe it would be best for me to get a shorter crank
The difference due to one pedal being further away from the centre line than the other is 'literally' negligible (<0.5mm)it [drive-side crank 5mm shorter] probably compensates for the drive-side pedal being further away from the centre of the bike because of the chainring.