The font on the k3 is dark. I guess you don't like it, but I do. Maybe you mean it's too bold? because I don't think the text can be too dark. You want it dark, right, for good contrast.
On the k3 you can install your own font and adjust the weight to exactly what you want. Problem solved.
To me, the font on the pw is both too fine and a bit faded, not as black as on the K3. I try all the fonts and the best one for me is helvetica, but it's not as dark as helvetica on k3.
I'm torn. Besides color blob issues, I like the k3 better for day reading. I have soent lots of time reading, switching between the two. With good bright light, the k3 is easier to read on for me. My eyes feel more relaxed. Besides darker text, the eink background is lighter. Despite what amazon claims, i think the k3 has naturally better contrast. I have to turn up the light on pw to around 8 to match the k3. Obviously, I can make the pw lighter by turning it up above 8, and in darker condition, the pw light wins.
One thing I notice about the pw is it is like LCD in one respect. It looks better when the room isn't so bright . Then the light does its work and you see the contrast. You don't want a dark room, though, because then the light unevenness and color blobs become prominent. So the optimal light condition for the pw is moderately bright room with Pw light around 15. For the k3, optimum is as bright as you can get without needing sun block
Given the k3 and pw in their respective optimal condition, I prefer the k3. The pw LOOKS nicer. I look at it and think yeah that's nice. But somehow when I start extended reading, the k3 feel better. I feel more relaxed. I'm not conscious about reading on a screen. Something about the light and the diffusion layer takes away from the eink experience.