I've had a PST since 1993 or so. It has come in handy on many, many occasions (including once when I used it as a weapon!). I've loosened it up to the point that it works like a butterfly knife now, so not even the gerber geeks have anything on me.
I also bought a supertool a while back, I carry it in my bike pouch (and I, too, have found several uses for the "bone saw"). Then, I bought a micra. I have a maglite solitaire hooked to it, so now I always have light and tools in my pocket. It's come in handy on several occasions when I needed to light my bubble level on my sticks before a late-night live shot, or for taking the door off my tape transport to clear a bad jam in the field.
The newest addition to my set has been a PST II. It isn't that much different from the PST to warrant replacement, but I found a brand new one for $25 at the Unclaimed Baggage Center in Scottsboro, AL. Couldn't pass it up.
Circle, the guarantee is 25 years, not life. Hurry up and send that one in before its too late!