The scandium frame makes for a lighter gun so it wont have the "heft" of a steel framed model. That also means that there will be more felt recoil. I'm not quite sure what you mean by the mechanism being a bit rough. They are mid-range production guns so right out of the box it wont have quite as smooth operation or trigger of the higher end guns but should get better after you get some rounds through it.
I've had two - a government model and a commander that is now my EDC. I prefer a steel frame for range use but really like the lighter scandium frame for carry. Both guns have been flawless performers, accurate, and reliable and I would not hesitate to recommend one to a friend.