One area where I know a wee little bit...

At one point in my life (I.e. Most of it), I was into knives pretty seriously (including knife sharpening, knife throwing, knife self defense (black belt), and custom knives).

I think I've tried almost all the knife sharpening methods & tools including the chefs choice (removed too much metal and motor went out like Rainman's), bench grinder with felt pads / paste, and more. Now rely on belt grinder like guy in following video. Works best for me.
http://r.search.yahoo.com/_ylt=A0LEV1L6VnRXYawAo2DBGOd_;_ylu=X3oDMTEyNnNoOXRlBGNvbG8DYmYxBHBvcwM0BHZ0aWQDQjE5MTFfMQRzZWMDc3I-/RV=2/RE=1467271034/RO=10/RU=http%3a%2f%2fwww.knifeforums.com%2fforums%2fshowtopic.php%3ftid%2f870724%2f/RK=0/RS=IWRGsU4ZodI9wSVLsovJfNx.w_k-

[Linked Image from i108.photobucket.com]