Hallo
I’ve just purchased a “tolino shine 2HD” e-ink ebook reader. The display is clear and easy to read and all the settings and controls are easy to find and use. It works well with Calibre 2.6.1 (installed from the Calibre website) running on Ubuntu Mate 15.10. The tolino reader was recognised by Calibre straight away, and I was able to use the Calibre menus to transfer books to the reader. 
I manage my DRM-free epub books in Calibre, but I don’t always want to read them on my computer screen. I was looking for an e-ink reader rather than a tablet as I prefer e-ink in the evening and when in bright sunlight. I was particularly concerned that the reader be “open” and allow transfer of any DRM-free epub books to it. The tolino reader is designed to be open from the ground up. The first book I’ll read on it will be Orwell’s 1984, secure in the knowledge that no one is going to remotely delete my copy. 
The tolino website: [http://mytolino.com//#]
People not living in one of the countries where tolino is available in book stores may be able to purchase it through other chanels e.g. in the UK from Amazon: [https://www.amazon.co.uk/tolino-media-GmbH-4016621123772-Tolino/dp/B017AAZ8FO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1467476913&sr=1-1&keywords=tolino+shine+2+hd]
The German speakers amongst us might find this video interesting https://www.youtube.com/watch?v=a-iootkazXo