I've learned a lot about handle to hand fit in the last two years or so, enough to say that it's a way more complicated subject then it appears to be on the surface.
The feedback that I've received tends to indicate that 50% or less favor the coke bottle shape. When questioned more deeply I've found that the fishing pole/hammer grip folks prefer the coke bottle while the pinch grippers don't. This also translates to slicing knives where a more full handle grip is used with say a pointed finger on the spine, coke bottle handles work here.
Also worth mentioning, at the risk of talking about my work too much here, is how I've made changes in my handle shapes that came directly from input of the users. The KEY feature that I've come appreciate is the area from the mid-to-tail hook section located on the bottom/sides as being the make or break area for proper fit up. In many of my earlier handles I made the mistake of leaving this too square and bulb-ish which tends to push the hand forward or just be uncomfortable as it splays the fingers (pinky & ring) slightly. I'm mentioning this because I've learned that the look and style of a handle means nothing - the actual fit is everything.....just something to consider.
This makes sense on many handles I've tried, and ones I have liked.