I to was looking for this lens for a wile. I got really lucky on this one, it's very clean overall and no defects, pretty good workmanship.
I paid much less for this one then I did for my Helios 40-2 and I'm not sure why but on avarage they cost less than Helios 40 but are much more rare and they are very rare in -2.
I've read that Sonnar 180/2.8 can brake after a while, in other words they are not as though as Soviet lenses. Russians overbuild most of their stuff anyway.
Few really quick test shots I took as soon as I got the lens.