Tried doing some research into this and haven't found much ... are there other knives (specifically Spydercos) that use the compression lock other than the PM2? My understanding is that Spyderco likes to experiment with different lock types but I haven't seen any other compression locks on the market, which is weird because it seems to be a super popular lock type (I know I love my all-black PM2). if there aren't any other compression lock Spydercos out there, what do you think the chances are that we see some new ones in the future?