During the 150 round quoted break-in period I had approximately 15% FTFs. No stovepipes, just pure FTFs. The barrel also has the same amount of wear from the slide after 150 rounds, if not more, as does my Glock 19.4 with approximately 3K rounds through it. The frequency of FTFs was the same across 2 different types of ammo and did not improve as I went towards the tail-end of the break-in period. This is reasonably high-quality ammo too, a mix of Fiocchi and American Eagle. All using their preferred Magpul pmag that came with the gun. Although not an expert shooter by any means, I've shot a couple local matches for fun and dry-fire regularly. I'm not one to immediately blame my equipment and double-checked my grip to make sure I'm not limp-wristing it or otherwise inducing malfunctions. The gun was also cleaned and oiled before I took it out for the break-in process.
SS quotes on their break-in period video on their Youtube channel that really the gun should be broken in a couple of mags in, which is like 30-45 rounds, and should maybe have 1-2 malfunctions due to their "tight tolerances." After calling their customer service, they said up to a 5% malfunction rate during the break-in period is within spec. Even after being at triple that, 2 weeks after initiating contact with their CS, I still have yet to even receive a shipping label to get it sent back in for eval.
I went to my 2 largest local gun stores, and they said my experience although not common, is what they've experienced before. They have great designs and can make good guns. There are just a fair number of lemons. Both stores have had to send back multiple guns. And their CS is known for being slow and unresponsive. And the turn-around time for service is on the order of weeks. From this information, it seems like even if they get the shipping label to me Monday, is that I'll probably get the gun back maybe in a month. 6 weeks+ turnaround time to fix a gun that I currently can't trust to carry or use in competition is bad. The lack of follow-through per their CS in conjunction with that is in my mind unacceptable. If another issue arises, I just don't have the confidence they'll take care of me and live up to what they promise on their website and social media.
If you google "reddit malfunction shadow systems" or "failure to feed" you'll see quite a few posts and threads with people having the same issues whether it's with their DR920s, MR920s, or even their newly released CR920.
At this point, I'm just completely soured on the brand and the gun no longer brings me any joy. I just want to send it back for a refund and to wait for the Walther PDP SD Pro to come out.