No need to wait until you need the Micro Suede pads. Their comfort is vastly superior to the synthetic leather pads. (They breathe better, and the material just feels softer.)
As for sound, I've found that they boost the sub-bass, give the mids a richer presence, and tame the treble a tiny bit.
If you do buy a pair to test, I bet you'll end up buying another. (They're that good. That's why Amazon can't keep them in stock.)