I've had both. Kobo is fine hardware-wise. And light years better on software than Kindle. One huge example: I have 1000+ books in Calibre. Took the time to tag them all into their respective categories. Kobo recognizes those tags and my book collection is sorted. With Kindle, I'd have to sort by hand on device. It ignores Calibre tags.

For this feature alone, I'd never go back to Kindle. Sure, I might be able to replicate it with jailbreaking + KOReader. But the Kobo worked this way out of the box.