The Zeiss-Opton Sonnar f1.5 on my Contax iiiA has 11 blades.. however at f2.8, f4, and f5.6 the circle is a jagged pattern. at other apertures, it is almost completely round.
Question: Wide open, arent most apertures completely round? It is certainly true for my Zuikos, where the aperture is completely out of the light path and a metal ring is all that is visible. Stopped down, you wont have much bokeh anyway.