My view,
After a year of testing/renting/forum posting and reading, i finaly went with th Arca Swiss Rm3di to, as arca simply gives for me the best solution and the only remainig open system...
Focussing, i also orderd on photokina the new " cloud " focussing system, wich reminds me a bit of the RF system one could get onbold Graflexes...
In base it looks real good as now you can realy see what your focussed on, plus its attached to the camera so you re always shure you measure from the correct distance...
Because its als linked to the focussing ring, the device show you exactly on how much distance you are actually focussed, so just mach up the numbers et voila...
I didnt get it yet ( half november ) but on the Kina it looked wicked ...
I became a big arca fan... Do all my work with it now...
So yes you can realy focus with the arca without a loupe, just compose under the cloth , turn the ring for focus and make the image ...
The point of DSLR, is valid but its just an other way of shooting, i still use my 645, but for other stuff, with a tech cam one goes back to basics, an thinks a lot more before taking the image ...