You should check out the Serif readability myth:<p><a href="http://asserttrue.blogspot.com/2013/01/the-serif-readability-myth.html" rel="nofollow">http://asserttrue.blogspot.com/2013/01/the-serif-readability...</a>
Personally, I don't really like that text is so big compared to the body width. I'd say you are getting a word-per-line average of 10 or so, way too low in my opinion.