I think the D112
basically just has more midrange than the 52... that's how it sounds, anyway. However, I'd also mention that the D112
(perhaps, because of having more midrange) seems to be a bit more sensitive to positioning.
One mic that we tried against a 52 recently was a PR40 (Heil), and we were really impressed. Thing is, the mic is SO DANG SMOOTH!!! The 52 is big and wooly (we went through identical TL tube pre's, keep in mind), and the PR40 is smoother and allows more sustain.
The ONLY thing to keep in mind with the PR40 - at least, what we found time and time again - is that the low end doesn't show up when you record it. You have to dial it in via eq, but boy... when you do, you'll find that you have the utmost versatility and low frequency response - far more control and low end than the 52.
I sold my PR40 months ago not realizing that it just needed a bit of eq loving. I think I'm going to be purchasing another again very soon... that and a 30 that I really loved on guitar cabs and floor tom. It KILLED a 421
on floor tom... we couldn't believe it.