Can you pinpoint why you like the Wilsons better?
I'll take a stab at it (I also like Wilson speakers very much, although I don't own a pair). I think with Wilson you really have the pinnacle of box speaker sound. Insane levels of detail and clarity, great transparency and prodigious percussive bass. The overall sound is dynamic, punchy and forward. Incredibly exciting to listen to. There's no "but". Just overall excellent speakers very well executed.
For the NX speakers, they are pretty much the pinnacle of open baffle sound. Which overall presents a sound with more depth (ie, literally the soundstage is much deeper), but the tradeoff is that the sound seems more "over there", further away, and less exciting and 'in your face' sounding. And the bass is also quite different. For the box speakers, it's just more tactile and physical. With OB's, it's more clean and precise and more like hearing actual musical instruments in your room.
Which is best? I think both are, it really comes down to preference.
I will say this - even though the NX series is less percussive than the Wilson speakers, the NX series is still world class at dynamics, just not 'quite' at the same level as the Wilsons. And on the flip side, the NX series is less boxy sounding than the Wiilsons, but the Wilsons are still less boxy sounding than the large majority of box speakers out there.