I have a black, blue dot Mamiya 135mm lens for my Mamiya TLRs.
I really like using it. It works well for portraits, as well as for landscape work. It is sharp, and gives good contrast.
It is also reasonably small and light.
It focuses as close as 90 cm, giving a 1:5.5 magnification ratio.
The camera and lens you have pictured shows a C220 with a chrome series lens. Your post mentions a C330. Is the camera and lens pictured the one you are considering? If so, you should be aware that it is difficult to obtain parts for the shutters in the chrome series lenses.
In case you don't already have it, here is a link to Graham Patterson's excellent Mamiya TLR resource:
Dead Link Removed
Graham also posts here on APUG.