Kobo original vs Kindle 3

I ordered Kobo and Kindle. Kobo is on the way to my home. I will properly get it this week. I have to wait Kindle next month. Anyway, I still can do some pre-research on them.
I am watching on following points.
1) Screen Size
Kobo: 6″
Kindle: 6″
Same size.
2) Screen greyscale level
Kobo: 8
Kindle: 16
Of course, Kindle can show more details on Carton books. But the real difference have to wait until I can compare them side by side.
3) Memory
Kobo: internal Storage Capacity 1 GB, Digital Storage Media Accepted SD, Included Memory Card 1 GB SD Card
Kindle: 4GB internal (approximately 3GB available for user content).
You can add your own big memory card into Kobo to have more books.Kindle can not, but 3G is big enough for me.
4) Supported ebook format
Kobo:Document Formats DRM ePub, PDF, Adobe DRM
Kindle: Kindle (AZW), TXT, PDF, Audible (Audible Enhanced (AA, AAX)), MP3, unprotected MOBI, PRC natively; HTML, DOC, JPEG, GIF, PNG, BMP through conversion.
Kindle support audio.

5) Library Support
It means I can borrow the book from public library. For example, Burnaby Public Library.

Library to Go allows you to download and listen to bestselling and classic audiobooks on your home computer, laptop, iPod, PDA and WMA/MP3 player. It also includes a large selection of e-books in PDF, EPUB and Mobipocket formats.

It needs OverDrive. Overdrive support Kobo only. Because Kindle does not support ePUB format.
If you want a Library friendly e-reader, Kindle is not your option. Here is a list of ebook-readers provided by Burnaby Public Library.
This is a very important feature. Because we go to library almost two times a month. My two daughters borrow 20 to 30 books each time. I just borrow two or three books. And when we are traveling to other city, we still can return or borrow the book online.
There are also some features I am not mentioned here. Including dictionary, battery life, weight, WiFi connection, speed open, etc.