The RMi series is made of very good PSUs, outstanding for a CWT platform.
But you're putting the RMi1000 against two units made by SuperFlower and Seasonic... which are higher tier for sure. The performance may be the same but the build quality... well, SF and SS are known to be two of the best PSU makers. However the RMi has a pretty long warranty so you'll be covered in case of problems...
It depends on the price. Can't tell which is better for you without knowing it