I can say that the square-ish, box-shaped Volkl grip seemed different to me when I switched into the C10 from my more traditional oval-shaped Wilson ProStaffs, but it was good for me in a couple of ways.
First off, I've always used a larger 4 5/8" grip size. Grip feel is quite a subjective issue for everyone and I definitely prefer a handle that "fills my hand" when I'm swinging a racquet. I've tried to use smaller grip sizes from several different companies, but when they get smaller, I quickly lose the feel of the bevels and my racquet angle can vary too much. Not all too confidence inspiring when my racquet face starts to wander.
Since I also go to the net a lot, I prefer a feeling of stability and control over the racquet for more authority on my volleys. Some of our pals here find it easier to swing through the ball with a smaller grip and I can't knock that if it works for anybody, but I've never had the impression that my larger grip made it tougher to make decent racquet speed. If anything, I think that when my grip is large enough for me (there's the catch), I have more positive contact with the racquet and can swing away with more control. That's just me.
Long story long... the Volkl grip profile (shape, etc.) feels bigger to me in comparison with other grips from other makers. On the other end of the spectrum, I've found the Prince 4 5/8" grip to be borderline small for me - more like a 4 1/2" grip from someone else.
I also switched into Volkl when I was retooling my ground strokes, including a one-handed backhand. For me, the bevels of a Volkl grip are easier to sense than the others - and I have many others in my collection. Finding the right grip position, especially with my one-hander, is significantly easier with my Volkls compared with anything else, including the more traditional oval. This simply means that I've found a "good fit".
While I see no downside to the shape of Volkl's handles, you may find that if you sample or even buy one, you may be more comfortable with one size smaller in the Volkl than you're used to... maybe not.