I'm not trying to hijack the thread - just wanted to share my experiences.
I currently have a large Sebenza and an Umnumzaan. I debated for a long while over which one to pick up as my "first" CRK.
I originally bought a large Sebenza, sold it, bought the Umnumzaan, and then went out and bought another large Sebenza.
I edc the Umnumzaan - it's appearance is definately more tactical than the Sebenza. I like the swedge near the tip of the blade, the discreet glassbreaker, and the grooves machined into the handles. I also like the curve cut into the back of the blade near the handles - it allows you to choke up on the knife and get much better control. I also really like the Grant & Gavin Hawk inspired pivot pin - it reminds me of my ZT 0500 MUDD and adds dramatically to the overall look of the knife. When I change out my HVAC filters, I have to use my knife to pull the old ones out since the slot that they fit in is very tight. The swedge on the back of the Umnum blade catches the filter once it pierces the cardboard side and allows the filter to be pulled easily out of the slot. I have trouble doing this with all my other knives as the backs are smooth and tapered - the blade pulls out of the filter wothout the filter leaving the slot. Just another bonus.
It's really a matter of preference - they are both great knives and you can't go wrong with either.
BTW - if you don't have a really good fixed blade yet - you should consider the Nyala. Out of all the smaller general purpose fixed blades I've tried the Nyala is in my top 3.