Probably just a 'one off' occurrence, but i was servicing the drag stack on one of my (yet to be used) SOM 16k NL spools last night and found 4 or 5 small sharp metal shavings between metal and carbontex washers and also in the bottom of the drag housing. It looks like they were left in from the spool machining process. A slight error in QA/QC on this spool only, none of the others I own have this problem.
I would hate to see what these shavings would have done to the drag stack under heavy drag and a big fish. Apart from that the spool is a very cool piece of design innovation as Enoch originally stated.