Something you can do is go to flickr and browse the lenses by the "tag" to give you an idea of the sorts of photos people are producing with either lens. This will give you an idea of which most fits with what you want.
Pentax 35mm Macro Limited Pentax DFA 100mm Macro
We also have "lens clubs" threads here but at the moment I can only find the one for the
35mm Limited. Perhaps someone else can provide a link to the DFA 100mm thread.
FWIW, I own both of these lenses, and they are both excellent. If you were asking because you are serious about getting a macro lens specifically, I'd say the 100mm hands-down. But for general shooting (including close-up options) it's the 35mm Limited all the way. The 35mm Limited is always in my bag (and often on my camera); the 100mm only comes out when I know I want to shoot macro.