Well it's not really a rifle, more of a pistol caliber carbine. As good as an AK? Depends on what you are using it for, it's not really better or worse as they are designed for completely different markets.
The Sub 2000 (mine is a 9mm with Glock magwell) is a handy folding carbine, sights are rudimentary as it is not really a long range gun, but they are quite usable at 50-100 yards. With 31 rounds and a light mounted on the optional lower rail it makes a dandy home defense or truck gun. If I had to use the weapon for longer range, or hunting, and my only other choice was an AK then I would take the AK. If it was for HD or a truck gun I'd go for the Sub 2000. Mine folded fits in a standard briefcase with 4 x 31 round mags, that's pretty handy.
I think it is simpler than an AK to operate, although until you get used to it that recoiling bolt can be annoying. To be honest though it's probably easier to shoot an AK , more conventional stock, easier to get your head in the right position, better sights.
So my choice was a Sub 2000, although I was only looking at it for a plinking/HD gun. For medium range or hunting there are other choices, the AR with a choice of uppers, SKS, SU16, HK SLB 2000, etc.