I bought a Kindle about a year ago. I loved it from the start. Its screen is just about perfect for reading. Sunlight is no problem whatsoever. You can easily keep reading for hours and hours without your eyes getting tired. It's so light that you can hold it in pretty much every way imaginable without it becoming uncomfortable. The process of buying ebooks on Amazon and getting them delivered on the device automatically is just great. The process of buying ebooks from other stores and uploading them to your Kindle is smooth enough, provided that you buy the books in the Mobi format. The battery life still impresses me, even though it's almost a year old.
I also bought an iPad 2 as soon as it came out. I didn't buy it thinking it could replace my Kindle. I bought it because I thought I'd prefer using it over my Macbook for the times when I just want to consume web-content, instead of actually working on something. If I want to work on something, I use the Macbook. For entertainment, the iPad is more often used because of its superior form factor and ease of use. After a while, you sort of get spoiled by the iPad and its interface. I now expect to be able to use my fingers when I see a small screen without a keyboard attached to it. The auto-rotating screen has also become a must-have to me. The fact that I can quickly switch between apps, without being visually distracted by them, is something that I absolutely love. And I expect everything to just happen instantly whenever I trigger something.
Simply put: the iPad has spoiled me so much, that I now sort of dislike using my Kindle. I know the Kindle screen is easier on the eyes for long reading sessions. I know that reading in daylight is much better on the Kindle than on the iPad. I also know that I really dislike navigating using the Kindle controls. I hate switching between portrait and landscape mode on the Kindle. I hate that everything I do makes me wait, even if it's only half a second. And I really don't like the fact that I've caught myself switching between both devices to check Twitter or email. So a while ago, I installed the Kindle app on my iPad and tried it for a while. I haven't used my Kindle since. That's not to say that I no longer think that the Kindle is a good device. In fact, for its price I think it's a great device. But it really just loses a lot of its attraction once you're used to an iPad.
For Amazon's sake, I hope the rumors about the Kindle tablet are all true. I think they're going to need to go in the tablet direction if they want the Kindle brand to remain relevant over the next couple of years. I do wonder what that's going to mean for the future of e-ink though.
Note: I actually wrote this post on my iPad, using IA Writer. It's the first time I'm writing a post on the iPad, and it's unlikely to be the last.