So yesterday the BR-05 brakes arrived and they look like indeed a step up from the old ones. The "lever" is longer, so i guess there is more force on the cilinder. Another great thing is the construction and setup is different which make for a better fitting of the calliper in my small size 52 rear triangle. I was fearing the slightly bigger new calliper would not fit, since the ZTTo once only barely fit, but the lever of the new calliper falls on the inside of the frame so the small angle of the rear triangle is no longer a problem.
I only tried the brakes on my driveway and the front one already seems a lot better than the ZTTO one...
I managed to f*ck up the rear brake by contaminating it with oil so I can't comment on that one. I was trying to get some (...a lot) of oil in the cable housing of the rear brake because the movement between cable and housing seemed rough and I guess it must have gotten on the calliper and pads... Turns out my rear brake cable was also worn where it enters the frame in the front, so I immediately ordered a compression-less Jagwire brake-cable set (the old was not compression-less) I am going to install in the next days. I will keep you updated...