For a very long time a CRK was the gold standard in tolerance, fit and finish. With the recent advent of CNC technology for production knives, the CRK lead on the rest of the industry has diminished. There are lots of companies out the making knives with great tolerance, fit and finish. But...there's more to CRK than that.
CRK also embody a great design, particularly the Sebenza. There's a beautiful simplicity in a high precision tool that functions perfectly. Not all the CNC shops can match that functionality, in fact many of the new precision CNC knives seem to LACK functionality.
CRKs also bring longevity. Because of the precise fit, they're a knife that you can use for 10 years then pass on with another 10 years of life in it. The CRK shop provides the kind of support needed to enable a lifetime of use.
Now...a couple of caveats. There are some folks for whom a CRK just doesn't work. If that happens to be you, it's not your fault and it's not he knife's fault. We all have different hands and brains and the same tool will never perform optimally for each person.
The other caveat...the Umnamzaan is fairly unique and has it's own learning curve. The opening action is distinct to it and it performs like a much larger knife than it really is. I have a Zaan and love it but I think I still prefer the small Sebenza 21 or the large Inkosi.
Precision, fit, finish, design, functionality, durability, simplicity and excellent support. CRK covers a lot of bases in terms of needs/expectations of a knife user.
Good luck and welcome to the dysfunctional, enabling neighborhood!