Might as well throw in my $0.02. I bought the small Inkosi after eyeing it since it first came out. I had a 25 for a few months but it was just too big for me to EDC, and I knew a small 25 would be awesome. Or so I thought.
I was stunned at how much the seemingly negligible difference with the small 21 impacted grip and (perceived) utility. the blade looked MUCH smaller, and while the handle of the 21 fits perfectly in my hand with a solid 4 finger grip, my pinky hung halfway off the handle and the top of the handle sank in my hand, instead of providing secure purchase.
The lockup was really late, and I could push the lock bar all the way through to almost 100% lockup without any effort. There was up and down play in the blade (I've had over half a dozen CRKs and they were all perfect...some slip by QC I guess).
The finger grooves were also not properly aligned with my fingers resulting in an awkward and somewhat uncomfortable grip.
The lockup issue I was disappointed in, but I knew CRK would take care of it if it was the only aspect holding me back. But I was honestly surprised at how weird this design was. For reference, I wear medium to large size gloves, depending on the brand.
And I now know the the small plain jane Insingo is the perfect package for me. It's the one I'm getting next (currently on the hunt for one). I've had the CF version and the micarta version and always preferred the utility of the insingo blade but the minimalist and simple design of the plain titanium handles that I've had on clip points.
Your mileage may vary.