Looking at the Borresens measurements I'm pretty sure that's a speaker that would grate on me over time. But we should be wary of taking our own subjective experiences and preferences and thinking they are universal. They won't be.
Agreed regarding universality of subjective preference.
I own a pair of X3s currently. They are one of my top three most satisfying speaker purchases among dozens over the past two decades. They are not “perfect,” but neither were the perfect-measuring speakers I’ve owned.
The non-linearities in their response would lead some to think the designer is clueless, however, they do make the X3s more enjoyable at moderate volumes relative to flatter speakers. The bass hump also compensates for the range where most rooms have a null when the speakers are positioned for optimal soundstaging (away from the walls).
Ironically, had Erin published that review before I acquired them, I probably wouldn’t have given the X3s a chance. I was quite firmly in the good graphs = good speaker camp.