Bokeh is stunningly beautiful with all 3 lenses—it’s so good you’re unlikely to better it with any lens. See the examples. Lovers of bokeh will want all three lenses because of bokeh alone—even without the tilt/shift!
Stopped down to the f/8 to f/11 range, bokeh is still just as beautiful.
One striking feature of all the Hartblei lenses, no doubt due to the wide coverage of their Zeiss optics, is that there are no funky off-center optical oddities eg so-called “cat’s eyes” or rotational-motion type effects off-center— just velvety-smooth out of focus areas. The symmetric optical designs correct most aberrations for a natural image rendition.
Even though equivalent Nikon or Canon 85mm or 50mm lenses have very nice bokeh in most cases, the Hartblei offerings are distinct, and in my view, preferable. The 12-bladed aperture cannot be alone responsible, but no doubt contributes significantly.
Here is one example of the smooth rendering available with the 120/4. Rendition is exceptionally smooth, with an absence of the distracting “bright ring” effect seen with many lenses. Examples from the corner of the unshifted frame at 50% of actual pixels. See also the color bokeh example.
The lens diaphragm is a 12-bladed design (!); nearly every lens from Nikon, Canon or Zeiss for 35mm cameras is a 9-bladed design, at most.
The almost perfectly circular aperture no doubt contributes to ultra-smooth out-of-focus rendition. More typical is 9 blades, so 12 blades is really outstanding. I checked the diaphragm shape, and they all stayed beautifully round at all apertures (not always the case with some lenses).
See the examples for what the lenses are capable of.