The Fast-R Nitro Elite 3 is PUMA's flagship racer. A carbon PWRPLATE sits inside NITROFOAM ELITE, the heel stack is 40 mm, and the 8 mm drop leaves a lot of foam under the heel. At 170 g it is one of the lightest shoes carrying that much stack.
It suits you on race day from the 10K to the marathon, once you are confident on a tall platform that moves under you. The ride is aggressive and it does not let you shuffle.
It is not a training shoe, and PUMA's own stated service life for it is short. The upper is minimal, the foam is fragile, and every easy mile you run in it is a mile you do not get on race day.