Its the ProEdge for me every time. Used grinding stones before, good, but I like the flat surface left after the grind. I can get perfect edges on any tool, flat, round, square, oval even curved, internally and externally. As an old engineer we had to sharpen everything by hand on any grinding stone, one of the tests one had to pass in old school engineering.
So, if a tool is out there and to make things easer, use it. And always buy from reputable sellers.
Kelvin