There have been some complaints about insufficient rear damping in the rear when Mazda 3 spec'ed Konis (especially the FSDs) are used on MS3s.
Lee Grimes at Koni recently bought an MS3 as his personal vehicle, and subsequently they've re-vamped their recommendations, and the actual kit that the they offer, for the MS3.
There is a TON of information regarding this stuff on one of the "other sites" that talk of is censored here, but that's the basic story.
I certainly wouldn't put the regular Mazda 3 spec'ed stuff on my car at this point, knowing what I've gathered from the guys that are running those setups, and after Koni themselves have changed their application offerings.