I saw the Bumpski guys today at the gun show and must say I'm really impressed with their work, especially when compared to the Slidefire AK stock.
I don't know if everybody will think the upgrades will be worth the extra $150 for the Bumpski, but I'm now a believer. I think I'm over my worries of hammer follow causing an OOB, now for me it is mostly a cost issue (ammo and stock). Comparing the two, the Bumpski is much more robust than the Slidefire and allows for use of what ever AK grip you prefer. Like the Slidefire, it allows you to lock out the bumpfire movement, but with three different positions similar to how an M4 stock works. On minor downside, is that both stocks are going to stop you from using your off shoulder if needs be, for now.