I thought maybe someone would answer here by now... All i know is, they seem to have a lower resale than some other doubles.
A big complaint i've heard is, what would be the "tang safety" on other guns, is really a cocking devise... Krieghoff has this too, but what makes guys not like Blasers design is, the fact that if you fire both bbls, open the gun, reload, you then have to cock it again manually! On the Krieghoff, opening the gun to reload is what recocks the hammers!
That's the big issue, and there's also some others that really boil down to personal taste...
BTW, Krieghoff's also have the bbl regulation wedge... as does a few others...
DM