You pointed out that the expectation document states "39ipm on duplex" which means 39 images per minute which is not the same as pages per minute. The difference is images vs. pages. Each duplex page has two images (one image per side.) So, at 39ipm duplex, you're actually getting ~19ppm.
I have a query about the ColorQube 9203. We print in fast colour mode which works at 85 pages per minute however when we do a booklet folded and stapled it slows right down and for a 36 page booklet (9 duplexed sheets) of 80gsm A4 we get 1 book a minute or what I estimate to be 18 pages per minute. Am I doing something wrong or is there a setting I am missing. We are using the PS driver and its a PDF.
Any ideas please?