There were a few things that moved me to Arca. Without belittling the Cambo in any way, the first was the build quality of the Arca is top notch, and IMHO the Cambo is a little behind here --- not bad mind you, just not in the same league for precision and smoothness as the Arca. Second was the precision of the tilt mechanism -- the Arca again is more precise and most importantly does zero accurately where the Cambo I demoed had enough play that a true zero was difficult to achieve reliably. The next thing was focus granularity -- the Arca helical is very fine and has a decent total throw for the range of tech lens focals, and being on the body you have no need to shim anything, simply make an offset calibration adjustment instead. Next was cost -- by the time you put three lenses in Cambo TS mounts, the total cost of the system was more than the Arca. Finally, I did own an F-Metric in my LF days and loved the precision, ease of use and self-locking adjustments -- and the RM3D carries that on, using similar precision self-locking rise, shift and tilt adjusters.
One significant point in favor of the Cambo, is with its TS lensmount you do get tilt AND swing at the same time -- not so with the Arca, only swing or tilt.
