From techradar

Pentax Q10 review: Noise and dynamic range | Digital slrs/hybrids Reviews | TechRadar

So looks like the Q10 has a nice 1 stop to 1.5 stops more DR at low ISO over the Q (that's quite significant btw) and better signal to noise ratio until we get to ISO 1600 and up where both are close.

So maybe that test I did where the Q10 was able to preserve colors better at high ISO is pretty real. This does clearly show a new sensor over the Q.

I decided to pass on the Q10 but I will probably get whatever Q next is assuming Pentax continues the same set of controls and if it has a new better sensor over the Q10.