Some of the test rides I took on 650s had poor braking because the dealer didn't properly bleed the brakes when performing the caliper recall. I made a point that following through with sale was dependent on the bike having good solid brakes, and it does. Adjusting the lever made a big difference also.
I now have a Brembo 4 pot, 65mm axial mount calliper fitted to my bike with a Brembo RCS MC. 330mm rotor on a custom bracket.
A bit of machine work to make it fit, and am thinking of how to make it a bit simpler so that most riders could do the mod