An AK is not in the same class as a large frame AR10, so, I don't consider those at all equivalent.

If you are interested in building/buying a primarily defensive weapon, a 308 based AR10 is the way to go. If you ever want to get into target shooting at ranges over 500m, want a "better" cartridge design for hunting, or wavy to take advantage of more modern ballistics overall, 6.5 Creedmoor is really hard to beat.

So, for the AR vs. AK thing... An AK is, essentially, more robust, if you get one that isn't half wonky. That being said, an AR is faster to reload in nearly all cases, has much better ergos, is much more modular, nearly any AR is actually more accurate, and will be generally easier to carry.

I am biased. I was in the army and my brain just functions on AR now. But, Stoner got so much right with the design, it's become the base to which one a few designs have exceeded its utility, practicality, strength to weight ratio, accuracy, and utility.

Though, I absolutely detest the 556, in general. That's a solvable problem, though, and I think it is good to have a rifle that shoots military loads.