Crank arm length: 172.5 vs 175. Is there an appreciable difference?

[KonaSS]

You will not notice the difference. If you road both back to back, maybe....but after 5 minutes your wouldn't. As long as your fit compensates for the change.

And as others have said, a lot of people are finding success moving to shorter cranks. At 5'11" I am moving all bikes to 170 (gravel, road, mtb). But only as I get a new bike. So still switch between cranks sizes with no problems.