For me, the orginal PSK is my most used blade (out of all my blades, not just my Gossman knives). The PSKsr, or mini Tusker would be next, followed by the WTK and the Kephart. The Kephart is my favorite blade of them all, but the PSK size lends itself so well to smaller tasks, I use it all the time. Need to get a PSKX. And a Tusker.
I have any number of Neckers, and I like my Becker a lot, love my Izula, but the PSK out shines them (IMHO). Been using mine for well over two years now, and I have beaten the heck out of it, and you can't really tell, and it still keeps an edge great.