As a handle for the primes currently available, the handle is not necessary in my opinion. I use it quite like the XF 55-200. Since one holds the camera immediately before triggering usually with the left hand on the lens, here the gain with respect to the holding comfort is manageable. With one hand, particularly when high take the camera provides the grip definitely a better grip.
But you have to remember that the camera At length with handle 86 grams and the volume (for example, when introducing into a camera bag) does not remain unaffected by the handle. Access to battery and memory card is possible. The battery compartment can be but without handle open and close a little easier.