Looks great, looking forward to hearing your thoughts vs the large 21 and 25. God willing, I receive my Umnumzaan tomorrow and it may be the lifer I'm looking for
You're gonna love that 'Zaan--it's just one helluva knife.
So anyway, I ate too much Valentine's candy, woke up in the middle of the night and can't get back to sleep. We're off to our woods up North later today, so I'll write now as everything from up there is off my phone with weak signal. This'll be a first impressions take on the comparison you asked for as it will take some time for me to actually use the new Inkosi--I want enjoy it's perfect brand-newness a while longer.
The thing with the Inkosi is that it's really the 25 re-branded and taken to another level. A lot of people thought that the 25 wasn't really a Sebenza as its adjustable pivot and ceramic ball interface were significant-enough differences that the 25 was really a new model. The 21 stands as the culmination of Sebenza development and the Inkosi now takes the 25 in the same direction.
I love the simplicity and purity of the bushing pivot on the 21. The knife is so well engineered and hand-fitted that you just crank the pivot down tight, the blade is perfectly centered, and the action is just the way the factory intended. That said, I like the action a little freer than the folks in Boise and take the washers on my 21s down .01-.02 mm each, re-polish them, and lately use W10 NanoOil instead of grease. Regardless, just tighten down that pivot and stop pin and the knife is rock-solid and immovable.
The Inkosi extends the design concepts of the 25 and follows the lead of the Umnumzaan with thicker blade stock and a large, adjustable pivot. The Inkosi adds the "floating" stop pin which solves the contradiction between an adjustable pivot and a fixed length stop pin. The larger washers add stability while the giant cut-outs reduce friction. My Inkosi was just the smoothest, freest CRK out-of-the-box that I've encountered and I likely won't be fooling with the action on this one. Overall, the Inkosi, like the 'Zaan is a more robust knife than my Sebenzas.
As to the blade shapes, each has it's place. I haven't cut anything with the Inkosi and so can't judge the new large-radius grind. However, the drop point blades have perhaps more utility with a fair amount of straight cutting edge, a generous belly, and a fine tip. On the other hand, I find the Insingo to be more useful on the job for minor wood-working touch-ups shaving, paring, and carving. The Insingo also seems the better slicer, but the two blades each have their uses.
So, after that wall of text, I think Lone_Wolfe has it right, as she usually does--get both!--though not everyone needs 125 CRKs.
PS: I just love the Micarta inlays on both my 21 Insingo and new Inkosi.