I play with my Viola Concerto bow nor for 15 months. It took me only one day to get used to it. The bow draws a big sound and makes very little noise; it sits perfectly on the string and allows any dynamic shading, up to a ponticello.
The lower weight is very welcome for me: It improves the comfort significantly when I play a lot and it provides a level of agility that I have never achieved with a wooden bow.
Every now and then I still use my good modern wooden bow, with out any problems in switching, as it pulls a somewhat different sound.
One of the violinists in my quartet has also purchased an Arcus bow after I explained the advantages to her, and she is also very happy with it.