This question pops up every now and then on here, and there was no real consensus when I asked a few months ago.
I think opinions varied based on the make, how coarse your beard is, and how belligerent the responders were. FWIW I resolved to change Feathers after every other shave as they blunt quite quickly, but if I was a bit tighter I might push them out to every other as it seems a bit wasteful, but I do like my blades ninja-sharp.