Chain -- NEX-5 & Minolta MC Macro Rokkor-QF 50mm f3.5. Click for larger.
At infinity, this lens is not as sharp as the Rokkor-PF 55mm f1.7. This is a compromise as most macro lenses are usually optimized for closeup performance rather than at infinity. There are exceptions, of course. The Carl Zeiss Makro S-Planar 60mm f2.8 is one of them. It's sharp at all distance. But, let's not compare a lens that costs about $40 to one that costs many times its price. As a macro lens, it's very good indeed. As a macro lens at such a cheap price, it's fantastic!
Bokeh -- NEX-5 & Minolta MC Macro Rokkor-QF 50mm f3.5. Click for larger.
I know some will turn their nose at this lens, as it has a rather small maximum aperture of f3.5. Really, macro lenses serve a different purpose than your fast f1.4 lens, although it can double as a normal 50mm lens. It's designed to perform best stopped down, and for macro, most of the time you want as much depth of field as you can get.
Compared to the 55mm f1.7 Rokkor, this lens is quite a bit larger and heavier, but still very compact without the 1:1 adapter. As with most MD/MC lenses (with some exceptions of course), this is one bargain of a lens, possibly the cheapest macro lens you can get from a well known manufacturer.
Lunch Time - NEX-5 & Minolta MC Macro Rokkor-QF 50mm f3.5.