I'm quite fond of my HK416. We have a plethora of weapons in our arms room from bullpups to SMGs to SWS'. I'm fond of some, less fond of others, but at the end of the day, I'm more comfortable with a particular design, ammo, etc. I think that's true for everyone. I can honestly say, I've never had a M4 fail on me either, nor a M16. But then, I take care of my weapons.
As for AKs, fun to shoot and keep around. Sure you can engage targets with them all day long, but they are a poor man's weapon and they are great for an undisciplined army. I certainly wouldn't take one when I need disciplined fire.
My quickly and simply written .02 cents.