I've never had a problem reading text on my blackberry, or even books on my iPad - but since I got a Kindle I do far, far prefer it to the iPad.
Maybe that's largely a personal opinion or maybe most people would agree with me, but either way my point is - yeah, it's not "too bad", and is perfectly fine, but it doesn't mean it's not significantly worse.
YMMV, but I found reading books on my transformer a lot more comfortable after I switched the kindle app over to white-on-black rather than black-on-white. It was enough that I almost gave up on my actual kindle for a while.
All this pre-retina? I find pre-retina text display blurry to the point of distraction after long periods of reading. Also, how do you hold your iPad? I like the newest and cheapest Kindle's size and weight for holding it an almost any position for long periods of time.
Maybe that's largely a personal opinion or maybe most people would agree with me, but either way my point is - yeah, it's not "too bad", and is perfectly fine, but it doesn't mean it's not significantly worse.