I found that (before anyone on here mentioned it), with the rMB, when used on my LAP, I felt I had to move it closer to me to read, as compared with the 13" MBA. Because of that, the angle of the screen was a little less than optimum when fully opened.
When used on a table or higher position for use, I didnt feel the LCD max opening issue was an issue.
I'd say this is more resolution related.