The best sharpening system I've tried is the Gatco system. Really foolproof and does multiple angles for different usages. As for razor sharp, again, it depends on the application. Too much angle and the blade dulls quickly. For my hunting knives I go with a 19 degree angle which is plenty sharp and much more durable, requiring less touch up. For kitchen type knives I can go up to 25 degrees of bevel. The beauty of the Gatco system is that you can do all those angles and the instructions in the kit tell you the appropriate angle application. And the kit is reasonably priced.