If you want smooth bokeh....
K-1 and F 70-210 ar 210mm and f-5.6.
K-3 and DA 18-135, ƒ8
K-1 and DA 55 at 55mm at ƒ2.
The round christmas tree lights in the back ground are definitely round, because they are circles of confusion, and circles of confusion are round. Take your simple magnifying glass out and produce a circle of confusion on the side walk. The circle of confusion will have sharp well defined edges. The only thing that might soften them up bit that I know of would be chromatic aberration. So it could be argued the DA 50 1.4 is smoother in the brighter out of focus areas would be it's notedly high CA values wide open. But the trade off with higher CA is less resolution.
K-1 and DA* 55 1.4 ƒ1.4
So yes all these things are subjective. But folks need to be aware that it's a sliding scale. You aren't just getting something, you're also losing something.
Just comparing the FA 50 macro and the new DFA 1.4, the DFA 50 1.4 has really good bokeh, but the FA 50 macro is sharper on the edges.gI'm not saying you need to apologize for liking one or the other. But you do need to realize, you're making a trade off. As above, looking at the F 70-210 image, the smoothest bokeh is from the softest lens.
The person shooting the 50 macro is saying "I prefer consistent edge to edge flat plane performance more than smooth out of focus areas."
The guys shooting the DFA*50 1.4 are saying, I prefer smooth out of focus rendering to consistent edge to edge performance.
The strength of the DFA 50 1.4 is it goes all in on the trade off. For smooth out of focus areas it's as good as it gets. And it's classic Pentax design like the 31 and 77. The FA 50 macro will remain the best edge to edge lens, although the edge resolution means the bokeh will get real sloppy really quick. People are going to pick a point on the sliding scale that suits them. Or buy all of them. Every individual lens defines a unique set of trade offs. None are the best for every purpose. But it might be the best set of compromises for the shot you're taking today.
Even with the DFA 50 1.4, better for you doesn't mean better for everyone.
It's sad that those who compare these lenses don't have comparative images to make their point. There are some somewhere posted on the forum, and the difference between the out of focus rendering of the DFA* 50 1.4 and DA* 55 1.4 was clear, but minimal. I studied those images carefully before opting for the DA*55 1.4. For some the little bit of extra smoothness is easily worth an extra $500, for others, not worth an extra dollar. The other advantages of the DA*55 , weight, volume of camera bag occupied and cost make it an un-appealing choice for the marginally better out of focus areas IMHO. The DA*55 is darn good, just not the absolute best at anything. But a very good and well thought out set of compromises.
Some people are going to prefer it.
It didn't get it's DA* designation by accident.