I'd love to hear what is so unreliable about it. Most often, the "unreliability" I've seen comes from people who don't buy the complete gun, and put an non-milspec lower on it, and don't put the proper buffer, spring, and buffer tube on the lower.
As for reliable enough to bet adopted, the M249, when using magazines is rightfully notorious as being highly unreliable. It is only reliable with belts.
As far as I know, they've been caught up for a long time.
I had six original Shrikes, and four MCRs. I never had one with the heat sink on the barrel, but from what I've heard, it's not worth it, meaning, it's not much more effective than without it, but, barrel cooling on the one inch thick barrel is great with that handguard.
No difference between the MCR's and the Shrikes, other than the inscription on the side. The MCR was originally made to lower production costs (passing the savings to you!!! Ha! Ha! Ha!) I never saw any differences at all.
The belt/magazine feed, gas piston operation, super-fast barrel change, much stronger bolt lugs, option for open bolt firing, meet all the criteria for a top Squad Automatic.
You can't have that old direct impingment on a SAW, those damn gas tubes will melt a whole thru them pretty quickly, and the heat put almost directly on the bolt lugs is the major cause of broken lugs.
But the Ares design, is a highly reliable weapon, (relatively speaking, it's not a Galil!!!!)
The one thing I really, really, don't like about it, is the charging handle has a lug, pulls back the bolt (of course), and it's got a whole thru it that the operating rod goes through. That walls of that whole, are so thin, that, in my opinion, they could easily break if the charging handle over-enthusiastically slammed back, to often, leaving you "Dead in the water". I talked to the inventor, Jeffrey Herring about it. He still thinks that part is strong enough, I still disagree. (but, who am I?)
I don't mean to offend any AR guys out there with the direct impingment comments, but that's why you'll never see a DI SAW.
Personally, I'm a Galil guy, though I envy the AR's fast mag changes, and "slightly" faster speed on target (of the lighter guns anyway) That's a huge advantage, for sure. Those "fractions of a second" can make "all the difference!!"
I do agree about the possible (probable?) loss of care for the civilian market, though the one time I had a problem, Jeffrey Herring himself got on the phone, and "talked me through it". Thanks Jeff! (I rather not talk about - the problem!)
I would wonder if there even would be a civilian market, if they get a big government contract! Maybe not.