Fiatlux

I think you should try both - usability/handling/personal preferences will matter more than IQ, IMHO.
 
I am a long time Nikon user (30y), with the D750 being my most recent camera, and have also developed a little Leica M system on the side - a luxury position I admit.
 
For the last few years I tended to use my M9 with 2-3 lenses for most of my pictures, and only use the Nikon for "action" photography. When the Fuji X system came out it looked like a good compromise and could potentially replace both my Nikon and Leica systems: nice selection of quality lenses, small size and weight, traditional controls I'm found of, convenience of AF...
 
After 2 years of testing the Fuji X system, I decided to resell it and keep my Nikon and Leica equipment. Image quality was not the issue and I find Fuji's lenses truly excellent (with perhaps the exception of the 18mm f/2 which, while good, is clearly not a match for the Nikon 28mm 1.8, not to mention the Summicron 28mm).
 
The main issues, to me, were:
my inability to totally "bind" with the EVF, in particular outside with strong sunlight where I often couldn't see much at all. I am a rangefinder lover so this may have biased my judgement; the sometimes unreliable AF behaviour, both in single AF (as with many contrast-based & hybrid AF based cameras, there is a tendency to sometimes focus on background items while I find PD-only cameras are better at identifying foreground elements) and continuous AF (I find Nikon's "group" AF tracking combined with Lock-On particularly efficient in fast-paced sports). But I've rarely been disappointed by the image quality coming from the Fujis

I do as well, especially on the second hand market, when priced accordingly. I'll offer 150$ - marks on the LCD are OK but optics need to be clean

I do as well, especially on the second hand market, when priced accordingly. I'll offer 150$ - marks on the LCD are OK but optics need to be clean

On the X-T1 I have the 23mm 1.4 and the pancake 27mm. I oscillated between both for a while. I love how sharp and useable the 23mm is and it just feels like image quality is a step above that of the 27mm. Whether it was the slight change in focal length (43mm equivalent) or the glass, or just me (likely) I was not happy with what the 27mm was producing. On the other hand, the size and weight of the 27mm is super convenient and effectively transforms the XT-1 into the smaller X100s form factor.
 
I chose to stick with the 23 mainly due to ergonomics of the aperture ring and the field of view being more to my taste. However you might want the 27 because of the form factor or the closer FL. it's a win win situation but these are matters of personal preference.
 
Ok my personal pov coming up next:
 
I don't buy the 'inconspicuous' thing. I think that's a big misconception in street photography. Your demeanour attitude confidence personality have a much larger role to play in my opinion. I decided to stop agonising over this issue, sold one of the lenses and for the past year have gotten used to that lens to the point where I know it so well I can focus on the image and my composition and because I am confident with my gear I get noticed less anyway. (Weight is not an issue for me either with the 23. I carry it around my neck or shoulder with those beatiful Japanese silk straps and it is supremely comfortable. )
 
Allow yourself to be "that guy with the camera " in your neighbourhood, don't be sneaky, talk to people who see you shooting, and soon you will be invisible. I accepted the fact that people will ask me what I am doing who I am shooting for why did I take their picture etc. then magically all of a sudden they stopped asking (well less and less).
 
I realise that's only one approach to street and that's my style and it suits me. It may not suit you but I hope to give you some input for your own journey. I know you only asked about a lens right? And some guy gets all preachy!! Sorry can't help it I love photography ;-)
 
Worry less about your lens choice and more about the opportunity cost of not shooting whilst you deliberate. You cannot go wrong with this wonderful set of tools. Good luck ;-)
 
 
Sent from my iPhone using Tapatalk

There are street photographers that shoot in 35 and even 50.  You going to go tell them that they aren't street photographers?  All the street photographers out there making a living with the X100 series, that aren't street photographers because they aren't shooting the right focal length.
 
I don't understand the need to feel that you aren't shooting street if you aren't shooting wider than 35.  That's a ridiculous and asinine statement if I've ever heard one.
 
Street is subject, not focal length.