I have a 3* system for my B4 and a 4* system for the ZX5. both have been trouble-free all season so far. I'm very pleased with them.
BUT .... I've noticed some of the motors come with
REALLY crappy bearings.
The vibrations generated by these could be the cause of the magnets on the rotor coming lose. My advice would be to check the ball bearings before running it and replacing them if needed.
The only other problems I've seen with the LRP/Nosram BL systems seem to be that some ESC's have a will of their own, demonstrating itself in resetting, engaging the overheat security for no apparent reason, ...