Well I have a K-01 and handled the Q for some time. The great advantage for the Q is that it is small (I only liked the prime 01 lens). It is handy, makes great movieclips and has good image quality at base settings (iso 125 and f3.2 is amazing).
Q with the 01 prime
It has the advantage for being small. The small sensor has the advantage for delivering nice sharpness in a good DOF (yes some people say that is a negative, but your hits are greater due to the bigger DOF).
On the other hand the K-01 can deliver on images that can be amazing, but also not very different from a K-5. It is a smaller camera that will grow on to you. With fast primes it will be a lovely camera. It on the other hand does give you a lot of the smae that a K-5 can deliver (+ focus peaking, better moviemode and faster processing on the 12-bit raw).
With the K-01 and FA31mm:
So I had for 15 days both of these with me and I did grab the Q more often, because it could do something my K-5 couldn't. I still purchased the K-01 because it is yellow and I love it by now.