Heil PR30 and PR40's get a lot of love around here lately.
General concerns about the D112's, Audix D6 and other traditional kick drum mic's is that they have an overall scoop built into them that can reduce bass frequencies... depending on your taste in bass tone.
Someone wanting a metal scooped type bass tone could love kick drum mic's on their cabinets.
Personally I've been using a cheap Samson Q-kick along with DI on my cabinets. It's inexpensive and seems to do really well without much of the others scoop. I however intend to snatch a Heil PR40 once I find an appropriate chance.