I use their Pro-E model as the arm provides a place to mount a flash and a RF transmitter for a remote flash and I can switch from a vertical to a horizontal shot and the flash stays in the proper orientation. The Pro-E with the quick release plate is very fast to set up and to take down as it is fully self contained.
When not using flash with a short lens I prefer the L bracket as I am not switching continually back and forth between camera orientations even when using tilt shift lenses for a panorama.
Custom Brackets makes first class gear that will hold up over the years. I would not hesitate to buy one of their products.
