I have been using mine for a while on a GR029 connect to Empire Pro brifters.
They took me a while to dial them in. I had BR02 first. These are piece of garbage and I wouldn't even use these as a paper weight. I changed the cable housing for Keb-SL (rear brake only) to try to improve things and it did not change much,
Then I got the BR05. First I had a very stiff control, I played with the cable hosing line and got something a little bit easier to pull but not better breaking. So i changed the pads for Tektro resin pads. Here I gat a way better performance.
Then I started feeling worsening performance when using a second wheelset. With a different set of disc, the brake path is not exactly lining up, so i ended up finding similar disc to the one I was using on the first wheelset, which are Juicy G2 160mm, I got cheap copies from mec.ca (in Canada) and now both wheelset brake fine.
TBH, I can't wait for Sensah to come up with the HRD empire brifter so I can upgrade to hydraulics. While the BR05 now work ok, it's still a workout for my hand when going down long descent and when comparing with Shimano, I feel it's day and night on how much effort is required to lock the wheel. This is probably due to the full length cable housing required for the rear brake.
In the end with buying to set of brakes, re-inforced cable housing, changing brake pads, sets of rotor (I tried 3 other set before coming on to these Juicy G2), I'm pretty sure I paid more then Juin Tech to get them to that level...