I had a Sebenza, and there's no doubt it is a fine knife, but for me, it wasn't perfect. I preferred a faster opening, deeper carry clip, and less belly, so for me, the sebenza wasn't worth it, in terms of opportunity cost. Sure, the $385 or so I paid for it was a fair price, given the precision, tolerances, etc, but that's not what sells a knife for me. I pay much closer attention to the steel, ease of carry, how much fun it is to play with, and a few other factors, and though the Sebenza is a great knife, it came up short on my checklist and I sold it. As for longevity, come on, just about every modern knife with quality materials will last longer than most people will. Look at how many slipjoints and Buck 110s have seen decades of use and are still functional. I don't think longevity is enough of a selling point.
If you want a flipper, get a flipper, because as good as the Sebenza is, it isn't a flipper. It isn't anything other than what it is

D), an all-Ti framelock with a thumbstud. If you really want a Sebenza, then get it, it really is great, but it won't cure your addiction and satisfy your wants just because it is a Sebenza. I ended up getting a Sage 1 and about $200 for mine, so that was a fair trade in my book.