well, there are two schools of thought on very overstable (anything more overstable than a fresh roc) midranges.
The first one is that they are necessary utility discs for get out of trouble, high winds, doglegs etc.
The second school of though (the one I subscribe to) is that very overstable mids are unnecessary and the shots they cover can be better accomplished by an overstable fairway driver.
I prefer powering down a fairway driver because: Overstable fairway drivers penetrate wind much better due to a more aerodynamic shape, and it keeps another mold out of my bag.