Originally, I purchased the 50-140 because I needed a telephoto for my available light kit (12mm f/2, 16mm f/1.4, 23mm f/1.4, and 56mm f/1.2 prime lenses).
After using it for a while, I preferred it for portraits over my 56.
The only thing I did not like was that it did not fit well in my fast available light prime kit. Eventually, I replaced it in the prime kit with an adapted 135mm f/2 Zeiss.
However, I was so pleased with the performance of the 50-140mm zoom that I bought the 16-55mm zoom to work with it. These two weather resistant lenses work well together when I do not want to carry my five primes.
16-55mm f/2.8 & 50-140mm f/2.8 Fuji Lenses
, on Flickr