I've got the Sulan Arms SDS tac-12, and I've wasted tons of time and money trying to get it up to snuff (although, that has effectively forced me to learn a lot about the ARGO system and Gunsmithing, and that aspect has been greatly enjoyed).
Most recently, the tip of the cartridge drop lever broke at the range! Previously, I had swapped out the sds extractor with a benelli oem, and it seemed to solve all of my stove pipe/ cycling problems.
So, I took it back to the range to speed fire 50 rounds because I wanted to make sure i could depend on this shotgun for home defense. After 6 shots, I noticed the bolt didn't catch on the last shell... so, I reloaded, and then shells wouldn't feed automatically... the trigger just dry fired, and I had to manually press the cartridge release lever and then charge it to feed another round... I was stumped... I was super bummed. I brought it home, disassembled everything and discovered the issue... then I went to freedom fighter and bought a newcreplacement cartridge drop lever...
While I had I had everything disassembled on the table, I reassessed the dependability. I've improved the cycling with better O-rings in the pistons (sds oem O-rings had disintegrated/ I purchased proper benelli O-rings), bought new wolf spring magazine spring, new recoil buffer spring, new extractor and extra detailed lube and cleaning...
Well, after assessing the remaining sds oem parts on my table, I think it'll finally be ok... all the other parts (barrel, Bolt, remaining trigger parts, etc) all seem solid... so, it should finally be dependable.
But, for now, my "go to" for home protection (which, hopefully will never be needed) is now my Ruger Mini-14 5.56 with expanding varmint rounds.
Last year, when I went to buy a shotgun, I didn't even want a semiautomatic- I wanted a basic pump, but the salesperson swore up and down that this clone was the bees knees... oh well, like I said, I've learned a lot, and may have quite possibly pushed this gun to a higher level of dependability... time will tell... more range sessions, more ammo...