Most people probably wouldn't notice unless it's an extreme change of length or they 5'2" like I am. So, just find what what feels good and go with it.
On my part, I definitely notice a difference. The socket for my right hand crank ended up damaged in a tumble and finding another 155 mm road chainset was near impossible. I tried 165 mm cranks until I could find something shorter. Huge mistake. I barely made it through 1 ride and had to be careful just flexing my knees to sit down in a chair for almost a week. Lucked out in finally finding a cycle shop who had 'left overs' of my out of production crankset and all was good again.
But, my knees aren't particularly healthy. I think the extra 2 cm diameter of pedal rotation was too much flex. So, I learned what works for me.
