Coming back to manual focus legacy lenses is really fun. This was about the first one I bought on a whim on ebay for a pittance and it's one of the better manual focus lenses on my shelf. It's actually the lens that got me into these legacy lenses and showed me the potential they have on modern cameras. I'm not saying that they're better than the newer lenses and the fancy coatings they have but it is fun using them and it has put something back into my photography thas was missing for some time.
It actually slows you down too and makes you think about your composition. Care is needed when focusing on m4/3 cameras as the peeking fuction implemented on the NEX cameras is sorely missing.