After watching Nutnfancy's review on the Blackhawk collapsible stock, I don't feel confident with it, nor did I beforehand. A collapsing stock on something as hard kicking as a 12 Gauge shotgun sounds like a bad idea, and for the Mossberg's safety placement, it's also counter-intuitive, as now the safety on the rear of the receiver is that much harder to reach with a lower grip and a stock in between the hand and the safety. I find that pistol grip stocks handle and feel better, but Mossberg has sort of dug its own grave with that particular battery of arms. A standard Mossberg semipistolgrip stock, I think, works best with all things considered.
Nutnfancy's review:
http://www.youtube.com/watch?v=I41htjbudh4