I only do Fem's that's unless I'm trying to cross strains or get seed. Which obviously, you need males but that would be the only reason I use Reg. Fem cuts down on the growing time when it comes to the plant showing sex sorta say, if I plant 6 Fem, and their all strong, good Pheno's. I know I should harvest 6. If Reg's, ....oh hell. I could get all Male and have to start over wasting weeks of time and money.
I have had only 1 plant go Herm on me throughout the years.