Every where i read it claims it can staple, fold, and fold and center staple (saddle stitch) up to 80 pages, including up to 208gsm (THICK2).
I have yet to get it to saddle stitch anything but plain paper. From both the fiery, and regular drivers, to just making copies and selecting booklet as the finishing option, it wont let me press start unless its set to plain paper, i have worked around but using 70lb in tray 1, but set it as plain (even though its THICK1.
The product support material all say 208gsm. See here on page 13 under finishing,
let me know if anyone has this solution, client is getting pissy as I steered him from a C500 to a C650.