I consider myself somewhat of an Amazon Kindle Connoisseur. I've had Kindles since the Kindle 2 was released and have had almost every model since then. The Kindle Paperwhite changed the game because of it's ability to light up the screen. You no longer had the problem of reading only in daylight or having to use a bulky light attachment (which I did with older models.)
The resolution on the Voyage is far superior to that of the Paperwhite. It's also lighter, has no bezel near the edge of the screen, and has little pressure point page turners (those lines and dots on the black border.) The refreshing of the pages is quicker and more seamless. The light is flawless and there are no areas that stay in shadow like my Paperwhite. The Paperwhite shows a little uneven light distribution towards the bottom of the screen.
I was worried about the new Origami case that was promoted with the Kindle Voyage. I went ahead and ordered it in "citron" (I would have liked to order it in "honey" like the Paperwhite case) and hoped for the best. I know a lot of people do not like the case but I find it very helpful. I really like how I can stand it up on a desk. This setup promotes multi-tasking; drinking coffee and reading, for example. I also set it up on my work desk and am able to read and work simultaneously. The Kindle itself is attached by magnets and the case is sturdy because of these magnets. While I do love that the Paperwhite case holds the kindle very snugly, I don't foresee a problem with my Voyage ever falling out of the origami case. And, the citron color is growing on me.
My conclusion? If you are obsessed with e-readers, and will put good use to the newest model--I say go for it. You will appreciate the improvements with the resolution, light, origami case, and overall sleekness of the Voyage. The Paperwhite is still a fantastic e-reader and worlds better than other e-readers out there. I gave mine to my boyfriend and he loves it. The Voyage is beautiful and I am happy to have it.
If you have any questions, please let me know. I obviously didn't get into specific specs of either model because it's all available on their amazon pages.