My Gen-12 upper arrived after 3 months in the production queue.  It is a 'drop-in' 12 ga magazine-fed shotgun upper that can be paired with an AR-10 lower.  Info is here - https://www.genesisarms.com/uppers



This is a pretty cool design with its short-recoil operation.  The barrel moves back about 1/2" with the bolt locked in during its initial travel, then stops while the bolt continues to move back & starts the extraction/ejection sequences.  
The upper came with a 5 round magazine but I bought a stack of 10 rounders to play with.  (Definitely need to make a mag coupler before I take this out to the match.)

My lower is a Sun Devil Manuf with standard 308 carbine spring & buffer and a Larue 2-stage trigger.  This lower was not listed on Genesis Arms compatibility web page but I figured why not, I do have a CMMG MK3 lower that is listed as being compatible so I do have a backup option.  All Gen-12 magazines fit and dropped free out of the Sun Devil lower.

Function-tested it yesterday with about 150 rounds of bird shots, 00 buck, and slugs.  The upper ran 100% with that mixed bag of ammo.  I didn't get to do any slug accuracy testing due to a broken optic, see below.

During function testing, my new Holosun 510C broke!  Its reflective glass detached and launched somewhere downrange.  I think the Vortex prism optic might hold up better, we shall see.

Perceived recoil-wise, the Gen-12 has a straight-back recoil, fairly stout, probably in between a Benelli M2 and M1.

I will do an update once I can get back out to the range.

Thats nice, spendy but nice. Ive been reluctant to buy one of the turkish ARish 12 gauge guns, just dont feel right. Basically shell guns.
That one is legit.

Is that a (5) or (10) round mag in the pic?

Def a 5rd mag

Yeah, I just found the mags on their site. The 10 rounders are MUCH bigger.

Love it.

That's a 5 rds. Fits better in the photo than the 10 rds.  They are currently testing a 20 rds drum .

I did look at the VR80 and the more expensive Orthus but I'd rather spend my money on the USA designed/built 'tools' like this one.  The Turkish guns are gas-operated, probably a little softer to shoot but I'm used to the Benelli inertia recoil so it is not noticeable.

I concur with you about the price, it is higher than those Turkish products but for competition use, most of the shooters I know spent more $ on their VR80 in the custom tuning shops to get them to run 100%.  With what I shot through this shotgun in function testing, I am sure the VR80s would have choked.  As an RO at matches in the past 20 years, I got a large collection of range pickup shotshells from 00 buck, cheap Wally World bulk pack craps, fancy AA target, and LEO grade slugs.  Some were pretty nasty looking with damaged crimp and surface rust.  I burned most of them up in one testing session .  Some magazines were loaded with the assortment of shells mentioned above to see if this upper would choke and not a single hiccup.  It was quite fun double-tapping slugs and buckshots onto the same target

Is this upper something that is intended for competition only or could it be used if the SHTF/defense weapon?

For me it is for comp only but just like any firearms, they can be deployed in multiple roles just fine.  If only for SHTF/defense purposes, I would get the 10.5".  They have even a shorter version but it is not listed on their webpage (yet).  You can see the shorty version in full auto 'Breacher 7.5" ' here -



The short-recoil operating system cycles super fast as you can see in that video.

A recent review done by TFB - https://www.thefirearmblog.com/blog/2021/10/06/genesis-arms-gen-12/