X100F or Leica Q2

I can speak to my experience.  In the past I have shot the Fuji X100 S and F.  Each time I bought the conversion lenses.    I ended up selling both.  Not because they were not good. They were my side kick camera to my system camera. Once was with Nikon the other with my Fuji X set up.  I have shot the xe-1. XT-1 and XH-1

two years ago ish i switched to Sony A7 iii.

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now I had the same idea Q2 or X100V. I did not need either having prime lenses that I felt covered the ranges of these cameras.  So I sold 3 Zeiss batis lenses and some video gear kept my A7iii and two zoom lenses

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the big differences. Yes cost , sensor size with megapixel count of the Leica.  Everything with the Leica is more expensive.  You want to use a 128 gb card with the Leica I think anyway.  The extra battery for the Leica and external flash options are also expensive and might be a necessary evil.  
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the X100v I am sure is a fine camera but Leica glass is beautiful. The Fuji has lots of menu options and I wish the Leica had a tilt screen but this Fuji is the first tilt screen and I lived with no tilt screen

what i did instead of buying 4 Fuji X100v cameras is get the Leica.

The reduction in mp does not matter at 75 mm it is good for at least a photo quality 8x10 print.

ask yourself do you need an extra Leica battery. Do you need a TTL flash for Leica is really the two biggest expenses.   You will also need a hand grip for the Q2 and I like RRS products and did that. 
when I shot Fuji I always use handgrips or Lplates as I’m on an Arca type system