I don't have any hands on yet, but I know several guys who own them. From what they've told me, they're really good mags and no disappontments from any of them.
I'm going to buy a ceiner kit and the full sized black dog mags so I can have some suppressed fun this spring so I won't have to switch to geico.:mrgreen:
I've seen several places sell them. Spikes Tactical comes to me first off the top of my head for about $30 each for the full sized (2nd gen) units if that helps any. If you can find a cheaper place to buy them, let me know.
For what it's worth, I'm picky about what I buy, and I'm getting some when I get the ceiner if that tells you anything.