I finally took the plunge on a Sebenza last summer, after 20 years of buying Spyderco, ZT, and numerous other brands. I went for the Sebenza, knowing that CRK's heat treat is inferior to that of many other makers, having edge rolling and inward deformation problems. I went for the Sebenza, knowing that CRK's implementation of the framelock (despite Reeve inventing the RIL!) is inferior to the framelocks of ZT and many other makers, having persistent lockstick and no overtravel stop. Despite all these things, I went for the Sebenza, and I'm so impressed by its total aspect that my thirst for other knives has dried up a lot.
If you can live with the design choices that CRK makes, many (but not all) of which are great, then you'll find that CRK's total execution of those choices is leagues beyond what the mainstream makers do. If that thought strikes your fancy, try one out. They hold their value better than almost any other knife, so there's little risk. I'm now a bit of a convert, and probably buying an Inkosi this year.
If you don't like CRK's design choices, then there are a few other emerging makers thee days in the $500-600 range who are worth considering, who I consider to be just as good in terms of precision craftsmanship and dedication to customer service.