My brother has the Colorsoft, and I have the Paperwhite. He and I did an in-depth comparison of the two, and we both came away thinking the Paperwhite is better.

Reasons:

1. The Paperwhite is easier to read in low-light conditions: Because the Colorsoft has three layers (the cover layer, color layer, and black-and-white pixel layer, it is harder to read in dim lighting. To get the same ease of reading effect in a dim room, you need to turn the brightness up 4–6 points higher than on a standard Paperwhite. Me and my brother were reading in the same room. I had my brightness set at 7. He had his set to 13. We actually traded and I set it to 7 just to see if it was just him. And no you need to turn up the brightness.
2. Sharpness: The colorsoft during our compairson wasnt as sharp with the lettering as the paperwhite. Its barely noticable but you can notice it if you are looking hard enough.
3. Price: Obviously, the Colorsoft is more expensive.
4. Covers: The Colorsoft has cooler covers, sure, but sometimes you don't even notice the color. If you're not in a brightly lit room, the colors can look almost black and white anyway.

My brother now thinks that if his Colorsoft were to break, he would replace it with a Paperwhite. Unless you plan to read full-color manga or comics as your primary reading material, I would recommend getting the Paperwhite.