I have owned several X100 models most recently the x100v and also the Leica Q2 and Q3. In my opinion as a 20+ year enthusiast the comparison is apples and oranges. Both systems have their strengths. If you love the Fujifilm system or are mainly a jpeg shooter, the x100vi is the one to buy. When I initially purchased the Q2, I quickly realized that this was intended for post processing. The jpegs were acceptable but not as robust as Fuji. The Q3 is solidly built with simple controls, tilt screen, an intuitive menu system, Summilux 28mm lens, 61 megapixels, weatherproof, IBIS, improved low light performance and dynamic range. If the Q3 is within your budget, my suggestion would be to try (or purchase) both and decide what fits your needs and style.