Not a fan of the current design. On the two I've shot on multiple occasions, both early models belonging to friends, the MS felt more like an afterthought than something designed with subconscious reliability in mind. The two things that stood out to me each time I shot their Shields...
1) This shoots like a much bigger gun
2) It took thought and effort to disengage the MS, requiring pressure from a very small spot in the inside of my knuckle to do it.
ETA: I could not sweep the MS with a normal firing grip. I had to draw the gun, loosen my grip to disable the safety with the inside of my thumb, then back to a firing grip. The same in reverse to engage the safety after coming off a target. This is why it took conscious effort.