I prefer my Copals because they have 7 straight blades so they make specular highlights and the sun have nice 14-bladed stars. This assumes I have everything in focus.
When I've gone for shorter DOF in my LF stuff, so far, I haven't seen any really ugly bokeh caused by aperture shape. I think the blur characteristics in these cases have tended to be acquired by the lens design. Now, in my Nikon 35mm system, the older AF-D lenses often have 7-bladed apertures, and those would in fact show ugly bokeh effects from the shape of the iris. But I feel like that's more due to the larger DOF of the smaller format. But I could be wrong.
I honestly would like to have a complete set of lenses on my 35mm DSLR with nice round apertures for portraits/people and one set with 7 or 9 bladed diaphragms for landscapes with specular highlights or the sun. If I was that crazy anyway (of course usually I use primes for landscapes and zooms for people so it all works out).