I started out with the Kobo Vox that the family bought me for Christmas last year. It was a breakthrough device - an eReader with Android for only $200! But I soon found that it it was greatly underpowered, making it infuriatingly slow and not much good for anything, except perhaps for a veerryyy patient person or one who couldn't afford any better.
Then I moved on to the RIM PlayBook (coincidentally even more Canadian than the KV!) And that was mucchh better, although I did experience some delays in getting a good eReader app from their non-Android app store. But I found this hardware to be first-rate, and a huge bargain now available at deep discount prices.
Finally, thoroughly enthralled with the 7in tablet format (and not being good at sharing with other family members) I bought the Nexus 7 last summer. And it's the best yet. With the quad-core processor it's lightning fast, and with true-Android O/S is promptly updatable. It supports all eReader apps and eBook stores, allowing free choice independent of any particular walled garden - and overcomes any reduction of choices resulting from our poorly-served Canadian market!.
I realize that these are all backlit tablets, which some here may not consider strictly-speaking true eReaders. But for my particular use I find the screen is perfectly adequate for extended periods of reading, and I greatly enjoy the ability to do eMail and run other apps on a multi-functional device.
Anyway, that's been this Canadian's experience, and my evolution eReader-wise for the past year, for what it's worth.