I don't have the 23. It's really hard for me to justify buying it when I still have an X100... so I can't compare them. You may well be right. Some reasons why I have gravitated towards the 35, (which has been a complete surprise for me, by the way):
- Bokeh. The slightly longer focal length of the 35 vs the 23 (or certainly the wider lenses) means I can blur that background whenever I want to, more easily than the wider 23 can do it. This is one reason I couldn't get decent portraits out of the X100 very often. I had to get so close to get a properly shallow depth of field, when that was wanted.
- Flatter perspective. I'm discovering how to use those longer focal lengths, how to stack things up on top of each other like a paper collage with mid-small apertures, and how to have a nice flat portrait. The 35 isn't AS good as the 56 at this, but it's close. This is the other reason I struggled with portraits on the X100... peoples faces warped a little.
- The lack of a push/pull clutch. Believe it or not, I've discovered that I don't prefer them now that we have the AF+MF option. It didn't work on my 14 f2.8 lens because you can't turn the focus ring unless you've pulled it into MF already, which sorta defeats the purpose. With the 35 it works perfectly. You're in auto focus, you half press, and then begin turning and POP, the 100% crop comes up, you fix the focus and finish the shutter press. It's so slick and intuitive.
- The 23 costs $250 more than the 35 right now. That's a cheap shot - it wouldn't matter once I'd bought them, but I think it matters to people who are considering buying both.
Let me be totally clear, though... I would LOVE to have the 23. I think it's worth what it costs, and then some. I suspect it's an amazing lens. But those little tidbits above, combined with $250 back in your pocket make the 35 the clear choice if I were buying today. NONE of this matters if you just prefer the 23's field of view, or if you really need the clutch, or you find the 35's AF too slow. It's so subjective...