I'll bite.
I've owned AK's, Mosins, and SKS's. I sold the AK's and Mosins and still have the SKS's.
AK - sucked for accuracy, ergonomics really do suck like folks say. Heavy with a full mag. Sure would probably run in sand/mud/SHTF, but so would an SKS. Stayed in the safe 9 range trips out of 10.
Mosin - built like a tank, but not THAT accurate for a bolt gun (I'm used to bolt remchesters that really ARE accurate). Kicked like a friggin' mule. LOUD as hell. Low capacity.
SKS - more accurate than the AK and about the same as the Mosin at 100yds, maybe better. Better balance and ergonomics. Doesn't kick like the Mosin. Weighs less than the AK with the full mag. Higher capacity than the Mosin. Easy to load with stripper clips. Just more fun to shoot than the other two.
It's a shame folks tapco-ize and bubba them to try to make them something they're not. For what they are, they're great. I'll keep a couple around just because of the stockpile of ammo I accumulated back in the super-cheap ammo days. YMMV