John, the 20mm f3,5 UD Nikkor bokeh is pleasant indeed.
Fons, I personally tried the Voigtlander 20mm f3,5 a few times when I saw one in camera stores, but I never liked what it gave me enough to buy one. And then I found my UD Nikkor for which I paid 27 Euros. That kind of solved my dilemma of wanting a small wide angle lens that would fit in a coat pocket. (the Voigtlander is considerably smaller though, but the UD Nikkor fit the bill close enoug)
I also own a 24mm f2,8 Nikkor-N.C which is another, even smaller, perfectly sharp wide angle lens. It is fairly well corrected as well, but wasn'treally wide on the D300 I was using back then.
It appears you are set up well enough in the 20mm FL to be happy with whatyou have

The only argument I could bring up is:


The UD Nikkor has to be one of the best looking lenses ever made for the F mount