When shooting architecture and when working in the field and you are switching between horizontal and vertical shooting on a regular basis it makes sense to have a method of working that reduces the effort, time and complexity of setting up for the next shot. I have the Manfrotto 410 gear head which has the PL10 a RC4 plate which allows for a fast switch between the two the main issue is the shift in the centre of gravity when shooting vertically. the camera is overhanging which isn’t an issue with a sturdy support but it does make the set up prone to vibration and wind movement.
Rotating the gear head alters the centre of gravity
Axis alignment and maintaining the centre of gravity
I have looked at a few L Brackets before deciding on the Manfrotto, I was concerned about weight, I walk a lot when on a shoot I need to carry everything between viewpoints so I want sturdy but not so heavy I need to dissemble the rig every time. Another issue is I use a grip this adds height and there needs to be a degree of adjustment to align the axis correctly.
Combined with the Manfrotto gear head you have the ability to adjust the levels accurately something a ball head can’t do well.