^^IMHO -It is just easier to sharpen on a regular bench stone. There is no set up. You just grab the knife and the stone and begin. You learn your preferred angles for different knives and then you can easily put a finer edge on a knife than the factory can.
Maintaining a perfect angle can be overrated. My freehand edge can cut anything just as precise as a preset angle edge.
Another reason to get a stone is that you get more sharpening space than a system. Most systems dont have a lot of sharpening space per stone. A big benchstone costs just as much, but you have 3-4-5 times the sharpening space. this makes it faster, easier, and more capable (it can handle larger knives too).
Either way -good decision to get a sharpener:thumbup: