I've got the Galco DAO for a 5.5" Redhawk and gave one to my Son with a 4" GP100. Very good holsters in my opinion. For the Redhawk it's the only holster I have found that carries the weight comfortably on a pants belt. I recommended the SAO to a friend for his 5.5" Bisley and he's happy with it as well. I like the option for both strong side or cross draw carry.
Dan