K-5 or a NEX7

I'm replacing my K-7 with something, just not sure what yet. Because I used a NEX5N I'm way impressed with that sensor compared to the K-7, I believe K-5 uses the same one. Obviously the NEX-7 has the bigger sensor, I wonder how the K-5 stacks up against it overall. Obviously the WR factor is appealing and unique with Pentax, I'm thinking of the 18-135 as an all purposer plus a dedicated fixed focal. For the NEX, I'm pretty impressed with the 16 mm fixed not sure what I'd stick on it as an all purpose.
I hate choices ...