What MeatAxe said in his latest post. Forget the AR for now. Cost and reliability are at the top of the list - Go with the AK or VZ. Personally I prefer the VZ. I'm not judging, I'm just saying.....
AKs are fine for a rifle role, but manual of arms is not ideal for a carbine. Perhaps less of an issue if you're comparing a more refined AK like the Galil ACE or Polish Tantal, but they're exceptions rather than the rule.
And though generally not a problem for AKs, with most with stamped receivers they can dent and render inoperable. Milled receivers may crack, but generally requires much more force -- the main issue w/ major damage is that stamped can generally be hammered back to function whereas milled *might* be able to be repaired with zealous welding.
On my thought process
My first semi-auto military variant rifle was the Galil in 5.56. I wanted a common round, utmost reliability, and something I could afford to shoot a lot of. With a magwell adapter, one can also run AR mags, but that wasn't a priority for me -- I prefer galil mags to ar mags. At the time, .223 steel case, which the Golani I purchased likes, was running around 15 cents a round IIRC -- and I was actually pretty torn between the Galil and a 5.45 AK at the time as to which was the best, especially considering that cost was a factor.
To caliber, 5.56/.223 does best out long barrels, so the 18" galil barrel struck me as an ideal length for a general purpose rifle in a caliber designed for best performance in 22-24" barrels...
Doing the same amount of research, wanting more in the way of effectiveness out of shorter barrels, wanting a carbine, etc, led me to concluding the VZ58 was the ideal carbine for my needs... The steal pricing on the VZ2008s helped to encourage me to take the jump too. And I am glad I did -- for all the reasons, I and others have covered here before. Carbine, I was primarily looking at the VZ, new production M1 carbines, and ARs... But now there are also other interesting carbines on the market -- the CZ805 Bren has me pretty intrigued actually, though all things considered I don't believe it's superior to the VZ58 for my needs, but in some respects the Bren is better.
Again, my personal bests for 5.56 general purpose rifle is the Galil and 7.62x39 carbine is the VZ58. However, neither of these are guns I am personally able, skills or tools, to tear completely apart and rebuild, when generally, I try to take a "don't own things I can't fix" approach to life, even if in running out of time I sometimes pay others to fix them... Newer weapons are much more serviceable in construction...
The AR15, b/c of it's light weight, is very well suited to a carbine role, but shorter barrels limit its effectiveness. However, a 16" barrel is a significant boost in velocity over the 10-14" barrels most commonly found on military issue weapons and discussed by Meataxe. The 16" barrel is common for accurized Recce builds as well (believe, if I have my facts straight, that navy seals/crane wanted the 16" recce vs the Army wanting a 20" DMR, so they compromised w/ an 18" spr weapon)...
An AR15 with a midlength gas system, decent barrel w/ optimized profile (not A2), free floated handguard, good but affordable trigger like Geissele G2S, a milspec bolt carrier w/ a good coating like NP3 (nickel teflon) or NiB, and add an optic, and you have a really good entry for first centerfire rifle when moving up from a 22lr and a cost effective one at that too...
My Mrs was never around firearms until me, and her first semi-auto was a 9mm AR (well, first I got her a Keltec sub2k but she didn't like all the plastic on a gun so it became mine) and is now a lightweight 5.56... She didn't care for the VZ58. So on prompting of wife and having family in the service whose primaries are ARs, I decided that might as well familiarize myself w/ the system. That familiarization led me to stop boycotting it out of principle/opinions similar to what Meataxe is voicing here.
In that journey, I've come to realize while not optimal, the AR isn't as bad as its reputation in some gun circles might suggest, if you're willing to upgrade components and buy quality from the start. Additionally, it does beat both the VZ58 and Galil in the accuracy department by a bit w/ a free floated and quality barrel -- and mounting optics is so incredibly easy vs those two weapons as well.
Lastly, and for many importantly, the AR is a much, much more cost effective system to get into. The Galil and VZ are actually pretty expensive if you price in not only initial weapon but also spare parts, deep mags, upgrade parts, etc. However on tradeoff, I also find the AR incredibly boring.
Anything beyond the range of these weapons, I believe a bolt action to be sufficient for my needs -- though semis are preferred. Military bolt, I really like my Swiss K31 and its surplus GP11 is the cheapest "match" ammo too in .308 equivalent calibers... However, I have been wanting to add some FALs to the collection, but have decided to only do so after adding an accurized .308 AR first... Probably going the RRA route to share same mags as the FALs.
Any need beyond .308 range, I'd be looking to bolt action .300 win mag (since more affordable .338 lapua or .50 bmg -- and I don't need to disable vehicles/penetrate armor which are the primary advantages of those larger and heavier calibers as I understand it vs the win mag). And with these larger calibers, the strength of a bolt action is also reassuring from a safety perspective.
I'm not saying anyone need to agree with me or even reach the same conclusions. Make up your own opinion but please do so on facts.
Probably iterated some of above previously in this thread, but might as well do so here to bring back on topic...
YMMV.