I have both and the difference is noticeable, if you see what I mean.
With the 23, I tend to take pictures of places and people in context. You have to get up close if you're photographing people. So you'd have to be comfortable with that. The 23 tends to be people and people with context. Not so much places.
The main difference is the depth of field when you're up "close". Clearly more depth with the 23.
The 23 is pretty sick. Super detailed and amazing rendering.
ejm8 got a reaction from D P in Have 35mm f1.4, want 23mm f1.4, but are they to close focal length wise?