My Buckaroo grandson uses a Yildez. 12ga now, had a 20ga but sold it for the 12ga.
Seem to be good guns. Very light, much lighter than a Stoeger.
He also has a very slicked up 12ga two trigger Stoeger and MUCH prefers the Yildez.
Both his Yildez have had a few problems, nothing unusual for a lower dollar gun, and nothing that myself or most any gunsmith could not handle.
Build quality is way above Stoeger.
My biggest fear with the Yildez is getting parts if I need them.
The 20ga is a different gun than the 12ga, different mechanisms (don't know why that is, but is). We seemed to have more problems with the 20 than the 12. The 20 had problems locking the barrels, had to get a gunsmith (Boomstick) to weld/work on the barrel locks. It also would light strike the left barrel, but that was pretty rare. The top lever that opens the barrels had problems too. The internals of the opening lever on his 20 was apparently made of soft metal and it wore completely out to where the gun would not open. Had to get it repaired with a hard weld and ground back down to specs. IMHO based on my experience with the 20ga, I'd stay away from it.
The only problem with the 12 was it not opening far enough and staying open enough for easy load and shuck. An easy but careful fix. There is a lug on the barrel, between the barrels, that cocks the hammers. The lug was too long and was over-cocking the hammers. This caused the hammer springs to keep tension on the lug and barrels not allowing he barrels to stay fulling open. By removing the butt stock I could see how far the gun was over cocking. Marked the hammers to where they cocked and carefully ground down the cocking lug on the barrels to reduce the over cocking problem. I just had to be very careful not to shorten the cocking lug too much, or the gun would be gunsmith bound. Works like a charm now.
That and the regular lightened hammer spring, polishing and chamber honing/widening.
Overall the Yildez 12ga is a great gun. IMHO
The internals of the Yildez are very similar to a Stoeger, so if you can work on a Stoeger you should be able to work on a Yildez.