I personally don't think the Winter sounds very DiMarzio. This is just my opinion, of course, not saying you're wrong, but I associate the DiMarzio midrange with a slightly vocal "Aw" sound. The Dominion I'd say is the closest DiMarzio to the Black Winter EQ-wise (although the Dominion is not nearly as hot), but the Dominion's midrange is really vocal/nasal. The Black Winter, while being very mid focused, is never nasal, IMO.
That being said, the Winter is certainly more wooly than the Nazgul. I'd say, however, the Distortion is more wooly than either. And that's just comparing them all, because in the grand scheme of things, none of them are nearly as wooly as, say, a Tone Zone.
If anything, I'd say the 'Winter's woolyness is easily fixed by just lowering the gain on the amp. It is, after all, higher output than both the Nazgul and the Distortion. It's REALLY hot. I had it in a guitar that also had an X2N, and it wasn't any less hot than the X2N.
JMO, of course.
And also, the D-Activator is an asymetric wind. So it matters which orientation you install it at. With the hotter coil towards the neck, it does take on more (loosely speaking) neck-y characteristics, which is exactly what you're describing it like. Quite honestly, the D Activator is one of the only DiMarzios I've ever really liked, just not in this guitar. I think its biggetst downfall is it sounds nothing like an EMG 81, LOL. But as a standalone balanced-ish medium-hot Ceramic pickup with a slightly nasty attack, it's pretty solid. It just doesn't sound like an active pickup whatsoever.