Believe it or not, I bought Opus for myself too.
I am actually a person who is looking towards powerful features in e-ink readers. And I have been very frustrated with the current progress. Except for Kindle dictionary, all other features are buggy, slow or otherwise unusable.
I want a reader that I could use for making notes, preferably pdf but the text format would be nice too. Kindle note-making feature is too slow. I want an e-reader that can display all major file formats (mobi, epub, docx, html, pdf etc.). I was looking for 10" screen but all the reviews have been so negative that I never dared to pay several hundred euros for it. I don't want to pay for an e-reader that announces all those features but in practice they are not very usable. Even the only thing that is good in the Kindle, the dictionary, has been crippled in Kindle Touch and Fire. What a disgrace!
Until someone makes such an e-reader, there is no use to punish myself by being early adopter using their half-finished products. The usable features in Opus are exactly the same as in any other reader. I don't need dictionary for Latvian books and the loading process is exactly the same as for the Kindle or any other reader (preparing files with Calibre and loading them via USB).
The difference is that Opus is lighter, smaller, easier to carry around. I didn't notice any difference in screen quality between Kindle and Opus. Kindle has darker letters but also darker background.
And of course, the current price is exactly what I expected to pay for it. I was lucky because I happened to be visiting the UK during these days.