Not sure if this is necessarily the thread to say it but since Sal mentioned putting a ton of work into this design I wanted to chime in with feedback. I've purchased both the Tenacious & the Persistence & will be getting the Resilience as well. My girlfriend edcs the Persistence.
What we both particularly like about these designs is the way the grind near the tang tapers back all the way to the edge. Not only is this (very) aesthetically pleasing but it allows us to use the entire blade length for cutting. I don't see many comments on this feature so I wanted to sound off about it. Most non-finger choil Spydercos would profit from this feature.
As for Sam's learning curve, I'd recommend handling a Delica, Caly 3, & Sage at some point if possible. Folks will make the world out of steel, lock ect. because we tend to focus on things that are easily quantifiable for side by side comparisons. And they do count, of course. But the most important factor (assuming a certain minimal quality of manufacture) is how it feels & handles in your hand. This is what makes this model such a winner. You'll easily triple your expense without getting better build quality, ergos or edge geometry (or looks, in my opinion).