Exposures are silent when using the V lenses via the "dumb" adapters.
With the exception of multicoating, the optical formulas for most (but not all) of these lenses are unchanged since the early silver lenses, although there were other updates to the shutter and apetrure controls and the focusing helicoids are smoother in the newer CF/CFi/CFE iterations.
Not all of these lenses were created equal. I routinely use the 100, 120 Makro-Planar and 250 Superachromat (all CF versions) on the X1D and they render beautifully. I suspect my 180 CF and 150 T* C (purchased new over 40 years ago!) would perform similarly. The 40 IF CFE is also stellar but in a quick comparison I found the native XCD 45 to control CA a bit better (as in, undetectable) even with CA corrections turned off in Phocus, something I found to be quite remarkable.
For me, at least, the choice to use these old warhorses is not so much economically driven but more based on gaps in the native lens lineup and the beautiful look that these old lenses give, even on these small pixel sensors. Plus, I already own them so it's satisfying to put them to good use. But where there's coverage in the native XCD lineup, I imagine these will out-perform the older designs in terms of resolution, micro-contrast and CA. As I mentioned above, it's simply remarkable. But whether this gives a more pleasing look is subjective. I must admit that I covet the XCD 90 for portraits, but am enjoying the old Zeiss glass in the meantime.
John