It's NOT a matter of personal choice. One weapon is better than another. What's lacking on most forums are trained and experienced soldiers who know better speaking up. After all, why would they want to given that most of the naysayers aren't part of the club, and spout anecdotal BS from unnamed third parties?
Here's a test that points out which has superior ergonomics: take an AR, an AK, ten mags each loaded with one round, and space them out down a table on the firing line.
Load and shoot the gun thru the ten mags, and time it. The AR wins. In the hands of a good shooter, the AR not only is faster, but also more accurate.
Since my last post, two things keep coming up, and it's smoke and mirrors: The cartridge isn't the issue - it's not about ammo. The OP proposed M16 vs. AK-47, and since both guns have been sold in both calibers, that's not the question. For every problem one might have, it's still a problem in the other gun. In science terms, it levels the playing field, and that leaves us with how the gun is used by the soldier. That's more important anyway.
The second sidetrack is tactics. How a small group manuevers and shoots depends on it's level of training, the amount that organization has updated it's doctrines, and what level of support the organization gives it. All that has nothing to do with which gun is better.
Most American shooters relate to traditional guns, and the romance of blued steel and walnut. They simply don't like or want change, it's not part of the culture, and something New doesn't fit into their mindset. What's ironic is that the American Army actually took The Great Leap Forward in adopting the M16, and they waited long enough to pick from the good designs already on the market.
While they likely wouldn't have considered the AK, look what else was available - the FNFAL, G3, M14, and a dozen others on the table in the 1950's. Ironically, none has survived, even downsized to an intermediate cartridge. The reason is ergonomics, not caliber. The other designs aren't all that easy to use, either. Right hand operating rods and safeties that force the user to lose their grip are a FAIL.
You can like whatever gun you want, but when the chips are down, 20 million Americans did quite well with the M16 in service, and the battle statistics show consistently lopsided results when others attempt combat against us. They LOSE. Even the Taliban know better to try an even fight, they'd rather use IED's, or forces far outnumbering us. Even then, they get hurt.
What's disappointing is that despite the obvious results of our use of the M16/M4 over the last 45 years, the general public remains in deep denial of what is obvious - the M16 works, and quite well. Perfect, no. Neither are the shooters themselves. And all too often, they blame the gun for their mistakes. After all, to them, it's about image and status, not facts. We're not a culture that raises men to be humble, more likely, it's preferred to be aggressively self promoting.
It's hard to discuss reality in an egocentric crowd of Donald Trumps. And those that prefer old school out of date guns they never used in the day seem to be the most vocal about what they can't possibly know about.
Typically American.