I have used both powders and am happy with RE22, but not so with H1000, this powder showed tendancies to go off on pressure excursions even when below published maximums, maybe due to inconsistent igniton?
Anyway, RE22 is a great powder in the 300WM and gives very uniform velocities/pressure.
An even better powder I've recently tried is RE25 which has given better accuracy than RE22 and even more uniform and higher velocity and lower pressure; standard deviations with this powder have been as low as 4 in Nosler custom brass.
If you would like the data for this powder you can PM me, and I will gladly share it with you.
PS. This is thoroughly tested data with a chronograph and inertial type pressure sensor.