I was there where you are now last November. I finally decided on the Opus (50 euro difference between the two) and don't regret one bit. Only recently I found these three reviews
http://www.techdigest.tv/2011/01/review_bookeen.html
http://www.girlguides.co.za/reviewer...-orizon-review
http://blog.chavant.info/2011/02/01/...-orizon-review
Since I didn't have Orizon in my hands to test it I don't know to what extend these reviews would be accurate for me. But it confirmed my decision to go for Opus for the time being. I would like to see how much darker the Orizon screen is than the one of Opus.