50mm lens for my K-5?

I'm siding on the DA 50 not having Quick-shift after reading feed back on amazon.com and Pentaxforums from real people and their point of view using them rather than a website "generalised" review. In each case they say it doesn't have Quick-shift.

Another interesting issue is Bokeh.

Its one of the reasons for buying prime lenses with large apertures, getting silky smooth out of focus backgrounds!

Generally speaking, the more diaphragm blades the better the bokeh:

50mm  f1.7 - 6 blades

50 mm F1.4 - 8 blades

DA 50 - 7 blades (curved)

Its all a bit of a compromise in the end and generally speaking the more you close down the aperture the more it diminishes in importance.

Still, a plus for the 1.4, on paper at least.