The Fuji X-T1 is the best camera I have ever owned by far. I wrote a review of it here if you are interested. The only thing I wasn't a huge fan of was the way it handled. There just wasn't quite enough grip to feel comfortable holding it. The vertical battery grip helps and I use that when doing my professional work, but it made the camera just a little bit to big for everyday use. It somewhat defeated the purpose of owning a small camera in the first place. I had also owned the regular size hand grip for my X-Pro 1 and didn't really like it either. It only was big enough for your pinky and ring finger and it just felt awkward.
I then saw the announcement that Fuji released this new larger hand grip and it seemed like it would be exactly what I needed. I ordered it right away and after a couple of weeks of use, I can say it is perfect for me. It just feels right when holding the camera. It also seems to make my hand more vertical when holding the camera which significantly reduces wrist strain. It does make the camera a bit bigger and heavier but I don't think that is all bad. A little bit of bulk makes the camera feel more substantial. Lenses like the 23mm and the 56mm fit perfectly while the 35mm and 18mm now seem a bit small. It also looks really good. It fits the look of the camera perfectly.
I am a big fan of this grip and love using the X-T1 more than ever. Pictures of it on my X-T1 with the 23mm f1.4 are posted below.