I'm thinking about buying a Work Sharp, either the MK2 or the Ken Onion edition. Is it worth the extra $50 - $60 difference for the Ken Onion edition? It would only be used for kitchen knives (RADA) and my pocketknives ( CRKT & Schrade folders & Boker otf auto). All my life I have used stones, but I'm having a harder time keeping my hand steady to get a good edge. Thanks