I've been using a Voigtlaender Nokton 58/1.4 for about a year now,
as a replacement for the M50/1.4 that I've had since the previous millennium.
The manual focus (on a K-x) is quite easy,
because of the central sharpness fully open.
The lens is ideal for portraits and bokeh shots at wide apertures,
and will outresolve most current sensors when stopped down.
Except for a little coma, it's almost optical perfection.
I didn't even consider the DA*55,
since I couldn't use it on my Pentax K-mount FF camera (LX),
and I don't like most plastic lenses or SDM motors,
although as Wheatfield's post makes clear, YMMV.
If you're interested in trying the Nokton,
Steve Gandy might be the person to contact --
Voigtlander SL II Lenses
-- since the big stores don't seem to have any now.