they are spoken of very highly from a mechanical perspective but every time I try to use my IIa on a regular basis I find myself reverting to the Leica.
-- focusing is weird, with that little thingy you have to push to release the lens lock.
-- viewfinder lack bright frames and was made before someone figured out that big bright viewfinders are nice.
--take-up spool falls out as yu are loading.
-- no parallax adjustment.
-- external viewfinders for all but the 50. On the other hand, the Zeiss external finder is really cool.
lenses are beyond first rate, however.
So, as a funky camera to play with it's great, but as a regular user I wonder. It's kind of a 50s experience...and my admiration for war photographers who used these things while dodging american/german bullets is extreme.
A IIIa also has a selinium cell meter that, lo these many years, is probably dead or at least inaccurate.
Having said all that, they fun to play with, If you can get a good deal, take it or live a life of regret.