OK. . . I watched (sand test and all) it and it looks like it'll work just fine. However I have a couple questions:
Is the reason you are looking into this because you're a lefty?
I've been shooting every type of firearm my whole life left handed and find that the AK is about the most lefty-user-friendly semi rifle that you can get. Never caught brass in the face. It's light enough that you can pretty much hold it with the pistol grip while keeping a sight picture and reloading.
How many folks have you talked to that have used the thing throughout thousands of rounds of shooting?
I'm curious as to how it affects the perfection of the AK. . . That is RELIABILITY!
Before I'd even consider it I would want to know from an independent tester how it functions outta the mud, sand, with no lubrication or cleaning extensively.
Looks like a good idea, but why mess with perfection?