Pocketbook Touch

I buy quite a few ebooks, mainly from Amazon and some from Kobo. Even though I had bad experiences with Amazon and Kobo hardware, I still feel a more confortable reading experience from an ebook reader than from a tablet or a pc.

Since I do not want an ebook reader "tied" to an ebook seller, I wonder if any of you has had a meaningful experience with the Pocketbook in conjunction with Calibre.

Thank you for your input.