I've had one for over two yrs. and it gets carried and used a lot. Lock-bar movement is one of the biggest concerns for Ti (RIL) frame-lock owners, and mine has only moved incrementally since new and currently sits at around 35/40% where it has remained since the first few months of use. Excellent considering the Sage 2's lock-bar face is left untreated.
I've experienced no lock rock or centering issues and the blade locks up solidly on every axis. Further, the bead blast finish Spyderco uses on the scales of the Sage 2 resists scratches, snail trails, and wear better than any other Ti folder I've had...on par, or perhaps even better than most stone washed finishes. The S30v performs well for most any task and sharpens fairly easily and holds a very sharp edge for a reasonably long time with moderate use, but can be a little chippy with hard use...however this is rare for most users and can easily be sharpened out.
Being a fan of 2.5 to 3" Ti framelocks, the Taichung Taiwan produced Spyderco Sage 2 and Techno (my absolute favorite EDC) have become my most carried and cherished folders I own and rival most any contemporary production folders (and some customs) currently produced. I wouldn't hesitate to recommend these knives to anyone...you could do far worse.