I started out with the Phase one cable, plus the wake up adapter. Recently I purchased one of the Kapture Group cables and have started to use it. I prefer it over the other method, as once you get into the flow, I find I get less errors on the camera. I have heard of them breaking, but mine has yet to fail. I have the shorter cable release and on the rm3di, it's a bit tight especially if you try to use the hole in the camera mount designed by Arca for the cable release. I am going to get a longer release which should help.
I have also started to use the Gepe short cable release extensions on my 35mm and 43mm as you can leave the extension on the lens and this makes screwing in the Kapture Group cable much easier since you don't have to reach up into such a tight space, especially on the 35mm. This is due to the fact that I have the physical CF on both of the lenses and it makes the space to screw in the cable release much tighter.