My "newer" is the MK7/8 look alike with the U shaped knurled channel - the older is the plain knurled cylinder.

I realize clicking isnt exclusively because of the extruder gear, but my other printer is set up identically and it seems to feed filament more positively - with less skipping in normal operation. The "older" gear seems to pick up more flament and become slicker with operation...

Although this is only going from my limited experience... I'm a firm believer in prevention is the best cure.