Well. I'm not a mic tech, but I've used a bunch of mics for recording acoustic guitar. My best advice is that it doesn't matter whether it is an SDC, an LDC, or somewhere in between. It helps if it's a *good* mic. I prefer mics with a little color on cheap guitars, and more transparent mics on really good guitard. I like brighter mics on boomy guitars, and darker mics on small bodied guitars. For nylon strings, I usually use a stereo pair backed off a bit. I'll just mention a few mics that haven't been mentioned that I sometimes use:
AKG C2000B- an SD mic in a larger housing. Ruler flat response, with a little color. The sound is very similar to Oktava MC012, but with better quality control, and much less prone to popping when used as a vocal mic.
Studio Projects C-4- a little bright, but one of the best stereo pair in its price range- comes with shock mounts and omni capsules, as well as cardioid. They are very good on a variety of acoustic instruments.
B.L.U.E. Bluebird- Less color than the Baby Bottle. Very good on a real good guitar.
That said, my personal preference tends toward the bright side of the equation. These days, I pretty much do all of my acoustic recording with an AKG C414B-ULS and a pair of Neumann KM184's. Not cheap, but they get the job done.-Richie