I don't know the technical specs for AK's, but of all the AK rifles I've owned, Arsenal had the best overall quality, fit and finish.
I've had a WASR10 (Romanian), 3 Saiga's (Russian), a Draco 12" Pistol (Romanian), and a M92 pistol (Serbian/Yugo). The Arsenal has the best exterior finish, the safety and mag release levers operate very smoothly out of the box, and any AK mag fits with no issue.
Some of the others had fitment issues with magazine being too tight/loose in the magwell, canted sights, tooling/scratch marks on the receiver, loose/rough machining, etc. Not to say that Arsenal won't put out a bad rifle here and there, but in general they inspect their rifles very well before shipping them out.