#16 - Looks very nice, try to make this one with the N from #16. I like the look of the slogan being stretched out under Dixirion. #19 - Looks great - simple and clean - I had not imagined green colours to be a possibility, but it looks nice. #17 and #18 - I would prefer a mark, company name and logo. Unless I could use the O as mark... The O and the N makes it "noisy" at the end. However, the idea with the O is not bad :)