Jim Saunders said:
The fact that the upright can be adjusted to center the camera over that axis is something to think about though.
That shouldn't be necessary with a bottom mount gimbal. The design of the gimbal should place the clamp centered over the base/tripod platform, and I'm not sure why you'd want to move it off-center. I believe the reason the vertical bar is clamped to the horizontal bar (rather than integrated) is so the gimbal can be easily disassembled for transport (as I mentioned for the RRS). However, with a side gimbal like mine, an adjustable vertical bar position is necessary to accommodate different lens sizes.