21mm alternatives

[pgs@pa.dec.com (Patrick Sobalvarro)]

I was wondering if people on the list had any experience with the
Japanese 21/2.8 Leica-thread-mount lens that's sold by Adorama.  I've
been looking for a lens this wide for some time.  I'm a little wary of
the Russar 20mm/5.6, because (a) my one experience with Russian lenses
(a 50mm/1.5 Jupiter) shows them not to have the best build quality,
and (b) I seem to remember someone on the list saying his own Russar
was not uniformly sharp across the frame.

Of course, I would buy a Leica 21mm lens by preference, but I didn't
see any older ones at the recent San Mateo show, where I might have
hoped for a bargain, and the $1500 that dealers on the Web seem to
want for used examples is a bit high for my taste -- I want a 21mm for
less than $1000.

I read a review of the Japanese 21mm, written by Tom Abrahamsson, in
the 4th quarter '95 Viewfinder.  It was kind of brief, saying mostly
that the lens was quite sharp but slightly less contrasty than the
Leica equivalent.  The Russar review I've read was in the late,
lamented online Photon magazine, and declared the Russar to be a
"cracker," a great lens.

Points in favor of the Russar: rave review from Photon.
Points against: questionable build quality, no RF coupling, slow.
Points for the Japanese 21mm: positive review from Viewfinder, RF
                              coupling, fast, good build quality.
Points against: reduced contrast, more expensive than the Russar

Can anyone add some info based on experience to help me out with this
comparison?

- -Patrick