I opted for the Mini because it fits my price range at £49, and I want to be able to borrow ebooks from my local library, (although I don't think there's a huge range, it's enough for me). Font/contrast/etc is very good - pls see photo. I have successfully downloaded Kobo desktop and ADE; downloaded some free ebooks from Kobobooks.com, and uploaded my own epub files onto the Mini with no problems at all.
I have not purchased any ebooks from the website yet, so that will be the next big test.