i thought about that and your point is well taken. i do a lot more shooting handheld in vertical. maybe i can figure out a way to get an L plate for xmas .
another advantage of an L plate is that it adds a layer of protection for the camera body. i carry my camera on my left shoulder, using an UpStrap. As such, the side of the camera that is wrapped with the L plate is facing toward the rear, protecting the body against accidental bumps when I am walking in tight quarters. I wouldn't say this is a reason to get an L plate, but its not an insignificant benefit.