Thomas, Indeed there are many who seem more concerned with lens signature, bokeh and even the seriel number. I have flirted with this myself, but now approach it with does the body fit my hand and eye well and is the bokeh distracting? If it's a good fit and the out of focus isn't distracting then it should do what I want. I can say I'm happy with the 1.7 50 and 3.5 135 for my pentax km (cheap and good) I love the 75 for my pentax 645 and will get a 150 for it sometime because it's a better fit for me than the 120 or 200. That will be the last gear I see myself buying for a long time.