Some things that stuck out for me sitting in on the the armorer class last Thursday.
Mechanically, it's as if they decided to take everything that was difficult about the M4, requiring complex and/or difficult procedures and requiring tools (sometimes very specific specialized tools) and make it simple on the SCAR. Like barrel changes. They're now a snap.
Sounds good huh? Wait for the other shoe to drop.
They then took everything that was simple about the M4, like detailed dis-assembly of the trigger assembly in the lower receiver or replacement of the extractor, and made them difficult, requiring tools, fixtures and, sometimes, a vise.
What does it all mean? Simple. Hell will freeze solid before Joe Regular Army ever gets his hands on one of these. It is a "system" and therefore too complex for Joe. Hell, the fuquin' thing is about two shades too complex for MY taste.
HK or LWRC piston upper receivers would have been faster, easier and cheaper. If I switch out a barrel on the SCAR, I still have to re-zero my optics. If I switch uppers on an M4 to change barrel lengths, my optics stay mounted for that barrel. Two pins and I'm in business.
The SCAR, as it is right now, is dumb. And, it's starting to look like we might be stuck with it. If they're still looking to replace the M4, Big Army should keep looking elsewhere.