I've looked at both the Yildiz and Stoegers and if I had to pick one I'd go with Yildiz:
1) The wood on the Yildiz is much, much better. Comparable to higher end O/Us.
2) The wood to metal finish on the Yildiz is excellent. Looks like a $1k gun. The Stoeger looks like it was finished with a grinder. Looks like a $400 gun.
3) Yildiz are exclusive to Academy. Academy sells some nice guns and seems to be a stand-up establishment (O/Us, semis, ARs, pistols, decent priced ammo, etc). Never heard anything bad about Academy. Stoegers are readily available at Dicks (same place that advertises Benelli O/Us that are really Franchi, doesn't sell any handguns, and overprices their ammo). Don't know a single person that has bought a gun at Dicks.
4) Anytime I've looked at a Yildiz at Academy the guys behind the counter are glowing and will let you hold every model. The guys typically know guns and mention that Yildiz is warrantied through Briley. Anytime I've looked at the Condor at Dicks the guys behind the counter could care less and know as much about guns as they do shoes.
5) The Yildiz is very, very light. If I were to buy one, I'd go with 20g over 12g. From what I hear, the 12g has bad recoil due to lightweight
I almost bought a Condor in .410 awhile back just for the heck of it. But even at $400, I couldn't get past the terrible workmanship.