I would have to re-do the plugin for fonts and margins if I reloaded the standard fonts. That would take time, so I probably won't be able to for a while. But as I recall, they looked about the same with the standard fonts relative to the way they look with the bolder one.

I still have trouble differentiating between the screens on my K3 and K4 as they both look good. One will look better in certain light and the other will look better in different light. But over all they are very close. Both are much better than the Kobo Touch I briefly owned, and it also had the Pearl screen. I sold my Sony 350 a few weeks before I got my K4, but the Pearl screen on it was close to that on the K3.

EDIT: I should mention that the more light that falls on an E Ink screen (without causing glare) the lighter the background will look. Also the type of light makes a difference. Incandescent, fluorescent, LEDs, and natural sunlight all have unique tones and hues.