I'm 6 foot with a 33 inch inseam. TBH crank arm length isn't so much of a big deal. I've been all over the map & honestly I think it comes down to personal preference.
On 170's I felt bound up after a while & for what ever reason it felt like my quads were being favored more. My speed/power remained the same.
On 175's my cadence noticably slowed, I feel like I pedal square unless I consciously make a deliberate round stroke, but after a while my hips started acting up. My speed/power remained the same.
For me, 172.5's seems to be the best happy medium from a personal physiology perspective. (Hip issue & pedal coordination.)
I found that 172.5's, for me anyway, paired with oval rings (Absolute Black, Rotor) seem to offer the smoothest power application & easily the highest cadence.
My wife is quite a bit shorter than I am. She uses 170's. For her 175's are a disaster. So, yes it does matter, but a lot of it is coordination & personal feel/preference.
If anything, you've got a powermeter crankset. It wouldn't be hard to sell it for a reasonably high percentage of it's "new" price.
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I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.