It's much too early to tell, but I am really happy. This is what I wanted the Pro 900 to be, but ended up getting rid of them twice because I couldn't make them work. I am noticing, possibly, a small lack of refinement compared to the Sig Pro. But again, this is straight out of the box.
Whereas the Pro 900 bass is boomy sometimes, this stays super tight. And the jackhammer highs are gone. It's not fair to compare this to the Pro 900 as these are on a whole other level. This is the refined man's bass can.