This fully manual lens is part of the "discovery" of using classic lens designs (or adapting old lenses) to modern digital cameras. On my M4/3 body is gives a field of view like a 50mm lens. Manual focus is much better than on old 1970's SLRs and "focus peaking" works well on camera that offer it.
For users who grew up with autofocus, auto everything, this is a step back to a time when photos were more carefully shot. I like using it quite a bit.