It depends what you're after, and how well you know P90s and what you're expecting from them?
I've got the original Mississippi Queens from some years ago. They moved through quite a few guitars and are now in Tokai Love Rock that I don't use very much.
It was my first experience of "P90" and I couldn't quite get to grips with how to use them.
Years later, I have quite a few guitars with P90s in. These are all routed for P90 (I probably wouldn't go HSP90 again myself - but never say never!)
Anyway, the ones where I've installed BKPs, I've used Blue Notes exclusively.
I found those are a lot closer to the "P90" vibe in my head.
I have a few Gibsons that I'm not going to change their pickups out - they're very close to the Blue Note, so I don't feel the need to change them.
My latest P90 guitar is a Fender Noventa Strat. I love the guitar, and the concept, but I've been struggling with the pickups.
And then I realised what it was ... I got the Love Rock out, and yes - the Noventa pickups are more in the Mississippi Queen ballpark - more snarly, and like Leslie West's tone in Mountain (duh!!)
SO, based on that, I'd say:
I prefer a smoother and rounder P90 tone - Blue Notes.
If you want the "snarly" type - Mississippi Queens.
I find you can get both to go in the direction of the other, but through the same amp set up, that's the difference I find between them.