Having own the K100D years ago when it first came out, and now owing the Q. Maybe its just my skill level... but I find the shots my Q are producing are much better in both contrast and sharpness. Yes, DOF is not as nice as a APS-C sensor, but it is adequate. Yes, higher ISO's do get noisy, but I'm happy at 800 and below. Without pixel peeping you can be very happy with the results.
The big thing about the Q and 01 prime isn't it's sharpness, bokeh, contrast, dynamic range..etc. etc... (which are all very good by the way), it's the fun factor and sheer enjoyment you get out of shooting with the little camera. Yes, I am infatuated with the Q. I've taken more photos in the past two weeks with my Q than I have in the last 6 with my K5. The reason isn't image quality, its sheer enjoyment and creativity the Q sparks for me. The K5 is a superior camera in every way shape and form. Even my K20D trumps the Q. It's cheasy, but the Q is a magical camera that you just wont want to put down. Just check out this
thread for image samples. You will find that people are taking just as awesome shots with the Q as they are their DSLR's.
So if the decision is K100D or Q for travel/walkabout... there is no question about it. The Q wins all day long, just on sheer size alone! Even compared to the Nikon 1, MFT, and Sony NEX offerings you can't beat the Q for daily walk about just because of the sheer size and ergonomics of it.
Until you buy it you won't understand. Until anyone buys the Q they will not understand. I didn't understand until I left research, data, and lab tests in the wind and just bought the thing. Once I did, I understood.