There is another one out on the market, but it's hefty price tag at $449 is a bit too much for me. I'll probably pick up an SSAK-47 stock sometime this year.
I have heard that a full-auto (or something that mimics a full-auto) is not that accurate in the hands of most shooters anyway. A semi-auto is a better choice for most situations. Plus, at $449, I could probably get a second AK. I think that would be a better use of my money (although City Girl would probably disagree).
People that never shot FA don't understand them...this stock may be expensive considering it's just plastic, BUT it's so much cheaper than a true FA weapon. Think in terms of suppressive fire...after all this is a SF. FA does have it's uses if something bad does happen.
For the most part, Hollywood did an excellent job documenting how a FA is not used. Suppression, recon by fire, even a "mad minute" to show what a line company has and to send an invite to dance. A pair of 7.62 semis positioned in a X fire mode would be quite a convincing deterrent also. Not as good as a belt feeder; but impressive in it's own right.
Read this before you buy one: http://www.survivalmonkey.com/forum/range-reports/29858-ssar-15-stock-review.html
As has been said time and again, the original akins accelerator used a spring which made it a mechanical device. The Slidefire does not use any sort of mechanical devices and requires your arm provide the forward force therefore it is still a semi automatic because each shot requires a deliberate action on the part of the user rather than the akin's spring providing the action after the initial trigger pull. Of course that is not to say the ATF can't or won't act above and beyond the law and ban them anyways.