I does really tap into that same pacing that Galaxy 2 and 3D World has where by the time you have digested one design idea, it jumps on to another. Little to no filler. Very happy with it.
I'd put it a tier below the top 3D platformers (which is mostly just the better end of 3D Mario games) for a couple of reasons, one being a preference from a more varied core moveset instead of spreading out to area-restricted options. The other is the visual design of enemies. These are gripes in name only though, just a couple of things a sequel can take care of to make it near perfect.
I can't see it not outselling Dread. Kind of hard to say how much Dread sold exactly with Nintendo not reporting on stuff that didn't sell a million within the quarter or something but we know that it topped 3m about 1.5-2 years ago so if I am to pull numbers out of my ass, I'd say it should be about 3.5 now, 4m tops (which by the way is pretty great for both Metroid and the genre, I don't know where the NOONE BOUGHT narrative is coming from).