When I compare my k3 and pw (bright room, front light "off", so both background are about same to make text comparison fair) my k3 text looks more like the pw in your pic and my pw looks more like the touch in your pic, except the difference is even more pronounced. The k3 text is both thicker stroked and darker, with less anti aliasing. The pw text is finer but faded, by which I means the black is grayer, almost like text color on kindle 2. The pw is better only in darker room, where its light makes the background lighter so my eyes feel like it's not working as hard.
Sorry, I don't have a decent camera or your skills, so I can't post pictures.
Btw, I personally don't think the touch is the gold standard for non lit eink. Ive seen two touches in person and both had darker background than my k3. There's a lot of variability with the k5 I think. It'd be interesting to hear from folks with the 2012 k5b.
Edit: looking again, I can see why some prefer the touch. The contrast is the same, but the pw has thicker strokes and more anti aliasing. It's almost like what you get if you set CSS text-shadow: #888 0 0 1px (grey shadow from center with 1px blur radius)
Last edited by Barty; 10-08-2012 at 10:46 AM.