Something most people leave out when looking at different rifles is "operator effectiveness". It isn't all about just the cartridge/accuracy/"reliability".
When your magazine runs dry, will you know?
How quickly and easily can you change magazines to get back into the fight?
Can you fumble it and cause a malfunction?
Now how about when you are laying prone?
What happens when you have a malfunction? (They all do, even AK's)
How easy is it to quickly diagnose and clear?
How easy is to go from safety on/patrol carry to "rock and roll"?
How does it perform when shooting 2 or 3 magazines in a row? Can you still hold the handguard or will you have to shoot one handed?
How does the rifle do in different lighting circumstances? Can you see and use the sights the same at 3:00 am as you can at 12 noon?
Can you get parts?
Can you get parts that will fit, or do you have to get parts specifically tied to your rifle's country of origin?
The rifle I have owned the longest is a Polytech AKS-762 that I bought back in 1997. I have more shooting time with it than any other rifle.
I am still better with an AR any day of the week.
I get much more bang for my buck with the AR than the AK because I am more "effective" at turning chemical energy to directed kinectic energy with it.
Now if all you want to do is blast rounds at a backstop. Which ever you like better and makes you feel cooler is the way to go.