I'm not sure I follow here, and I apologize if I'm belaboring the obvious. Was the question about carrying closer to the belt line or actually dropping below the belt line? I have one holster (Silent Thunder from Garrett for Glock 26) that rides close to the belt. The grip of the pistol is completely above the belt, but I don't have as much clearance for my fingers as I do on my DSG or JMCK holsters. Consequently, establishing my grip, and thus my draw, takes longer. Because of the lower ride height, the G26 in this holster conceals a little better for me than a G19 in DSG/JMCK. It's definitely a trade off though, as my draw is slower, capacity is lower, sight radius is shorter that a G19 in a JMCK/DSG, but it's still better for me than a J-frame.
Sinking lower in the belt would be Dale Fricke's Jonathan (
LINK). I view that as a niche holster, and it's not something I've ever needed. I have a JMCK Universal for my G43 that works very well for when I'm most concerned about concealment. This holster also rides close to the belt. I'm about 0.5 seconds slower on the draw with my G43 in the Universal than I am with my G19 in a Wing Claw.