tradlongbow: As you can see, I have small hands and a grip that deep may seem counter-intuitive. Yet, I've found that the deeper grip doesn't allow a lot of latitude in how I grip it. The back of the grip is solidly against my lifeline, the front of the grip is under the middle pads of my fingers. I don't have much contact with the side of the grip, at all.
I usually practice with six or eight arrows at any given range, working on my form. I have found that the deeper grip gives me fewer options on varying my grip from shot to shot, resulting in tighter groups. The deeper grip, I believe, is less likely torque on me, whether I am holding it firmly, or "squeezing the sap out of it". Again, the pressure remains against the lifeline and the middle pads of my fingers.
If anything, the grip is a little more rounded towards the back, rather than the "old school" wedge shape I have come to prefer. I reserve the right to break out my trusty wood rasp at some point in the future....
Be well and good luck,
Bob