Mine came attached to the M3 I bought a couple of years ago. It does suffer from haze and cleaning marks and I only use it infrequently as a "special effects" lens - the softness does make for good, atmospheric and gentle portraits for example. It is not dissimilar from the LTM Summar I also have, so does posess that famed glow.
If you have found one at a good price then it's certainly worth picking up and having a play with it to see what it can produce. You may be pleasantly surprised.