For six months in AFG I wore the issue Bianchi drop leg holster. My work was indoors in chairs, and sometimes I rode in a civilian vehicles. Until you've worn a fullsize handgun every waking hour, it is hard to imagine how noticeable the weight, the heft and the imbalance it imposes.
For example, I don't wear my pants cinched tight. I wear a t-shirt tucked in and my belt tight enough to hold my pants above my hips. In warm weather a tight belt and the extra weight began to chafe. The drop leg redistributes the weight off a narrow surface on the waist to the thigh. Second, a proper holster holds the handgun firmly. If it is on the belt, the butt droops as it snags on things like seat backs and arm rests. (I know, I know, REMF problems.) The Canadian combat shirt hangs long and it covers the holster. Between drawstrings, buttons open or fastened, stuff in pockets, and a natural drape, hoicking the shirt hem over a holster gets uncomfortable after a while. Therefore, I found that as imperfect the Low Cost Bidder Bianchi is, I could carry the pistol on my leg and unconsciously roll it 90-deg from the side of my leg to sitting on top quite comfortably.