I must admit, I'm one of the folks who uses calibrated sets and nothing else. So far for me it's as follows:
Mules
Riff Raffs
Stormy Mondays
Mississippi Queens
Irish Tours
Apaches
Sultans
Yardbirds
Blackguard (Original) Flat 50s
I often find myself wondering why lots of folks head for mixing and matching so quickly, especially when the calibrated sets do such a good job. But, on the other hand, I'm not looking for "several guitars in one guitar" anymore.
So, maybe, when I first came across BKPs, I was already primed for "OK, what's the recommended set then? Take my money now!"

Possibly, if you forced me to cut down the number of humbucking guitars I own, I'd start getting tempted to try the RR/Mule combos or maybe RR/MQ or Mule/MQ. But all my guitars do what I need them to do, and the calibrated pairs really do work together very well.
BTW, I'm even more surprised when folks start mixing and matching strat pickup sets (SSS I'm talking about here) - I personally can't see any way that I'd want to do that!
But I can see how other folks would need to do it, everyone's different.
Oh, and, although I've not tried Abraxas or BD, I have been checking them out and one might be my next set (BD, I think), but for this case, and everything I understand about them so far, I think I'd be going for an Abraxas set myself.