I read Stanley Morison article ‘Towards An Ideal Italic’, The Fleuron Number 5 (1926) pp. 93-129. He proposes the sloped roman as an alternative, because he wanted the 'ideal italic' to blend in better with its roman counter part. The reasons he gives in his article for an ideal italic are (in my opinion) reasonable. However the only example I know of and have seen of a design based on Morissons article is the 'Romulus schuine romein' designed by Jan van Krimpen and to my knowledge Morrisson never followed his own advice. I have seen the drawings of Romulus (including his slanted roman) and I have read Van Kimpens own dislike for his experiment.
I was wondering if any of you know of another design for a serif typeface with a sloped roman (except Romulus, Perpetua and Felicity) and could you explain the dislike or like you might have towards the sloped roman. I want to find an explanation why (for example) the Romulus sloped roman was never successful and an Italic had to be designed. (Readers couldn't keep the roman and sloped roman apart? But the reader can keep many more letters apart.)
If you by any chance know of a book or article about the subject (the sloped roman) I would be much obliged if you give me a title and or author.
I found the following Typophile topic:
Sloped roman and italic in the same family http://typophile.com/node/4088