Thanks for the response Nero, you make a lot of good points. I'm fairly locked into being a landscape shooter, I shoot wildlife too but with my 55-200 (I wish I could afford the 100-400) and I think you're right about maybe having both 23 and 16 in the long run, especially if an f2 version of the 16 comes out. It sounds like your style is similar to mine - I'm usually exploring multiple places, usually hiking with my girlfriend. Thankfully she's very patient but that doesn't stop me wanting to get the job done as soon as possible and keep it moving. The 23 would be great for everyday walkabout I'm sure, I often find my 35f2 too tight. I agree completely about not wanting to swap lenses all the time, but for me that's countered by having a choice of small lenses rather than one large one - many times I'll just take a single lens out on a walk or pocket a backup lens.
I think I'm sold on 23 at this point, and like you said, back it up in the future with a 16f2 if it comes out or maybe the rumoured 8-16 (I'd probably be OK with an ultra wide zoom, so long as it's good for Astro).
Thanks!
For anyone that was interested, I just yesterday made a website for my photos - I'd love some feedback!
All shot with X-T1, Samyang 12 f2, XF 35 f2 or XF 55-200 - who says you need expensive gear to get results!?
www.surfcoastnature.com