We do make a Touch-Up OmniShaver that is designed to reach behind the ears. We feel that the Touch-Up OmniShaver and the original OmniShaver work really well together, with the original OmniShaver being able to shave 95% of the scalp very quickly and the Touch-Up OmniShaver can be added to reach difficult areas like behind the ears.
See Touch-Up Video: https://www.youtube.com/watch?v=udJMXTU6qtE
We've made countless cage/handle prototypes, trying different combinations of rounded surfaces all the way to rubber infused grips and in soapy or very slippery conditions, none of these prototypes could maintain the grip that our current cage handle provides. I know that some of the angles are a bit sharp, and if you look closely, you'll see that even the tip of the arrows are exposed to give more grip. All of these contours are purposely designed into the cage handle for maximum grip performance. The bottom line is that we thought when guys are shaving their heads in the shower or when legs are being shaved in soapy bath tubs, the OmniShaver needs to be controlled in those environments and that's what we've accomplished. We do have an extension handle that will fit on the OmniShaver you currently have but it won't be ready for another couple months. I hope this explains our designed decisions and I hope you'd give our new products a try.