I was recently shipped a 16mm 2.8 lens mistakenly - I'd actually ordered the 23mm 2.0. I'm the proud owner of a new XT-30. For the moment, I have both lenses in hand. I have 30 days to send one of the lenses back. I confirmed what I saw in many reviews that the 23mm is soft when wide open at 2.0. That does not seem to be the case with the 16mm at it's maximum aperature (then again, it can't get that wide.) I also noticed that the f-stop clicks were much more distinct on the 16mm than they were on the 23mm, although I doubt I would have noticed it had I not compared them side by side. I will say the 23mm feels a little better balanced in my hands with the XT-30 than does the 16mm.
Now I'm struggling over which to return. I think the 23mm is a better fit as a 'standard lens' - at least the way I shoot. On the other hand, the other stuff I mentioned above sort of sticks in my craw.
Any opinions along these lines are appreciated. Thanks in advance!
Al