I assume you are talking about XTR 9120 4POTs.
Best brake I have ever owned. I slapped the brakes on my bike, cut the lines and bled in about 20min and they ride borderline perfect out of the box. I am so impressed with these brakes. I will say this even if cliche....these brakes let me ride faster because I have confidence not just in slowing down, but how I will slow down....under control. They are still Shimano in feel (I had Magura MT7 before this), but way more modulation and the power is downright crazy.