Not to belabor the point, but aside from plasticy feel of shifting with the Sora, what is so inferior about them?

As for cable stretch, you just may have to adjust the derailleurs for cable stretch as time goes by (unless you have already owned the Microshifts for a while). Cable stretch should not improve anything. New cables will shift perfectly and as they stretch, gradually make shifting worse--they will turn a properly adjusted drivetrain into one that does not shift properly and will need to be adjusted--usually loosening up the adjustment barrels. If your Absolute is new, it should shift perfectly unless it is not adjusted properly or components are damaged.