What's your preference for knife sharpening?
I use water stones for kitchen knives, which for the most part have straight edges or a very slight curvature. I used water stones for some of my folding knives, but I have been using the stick type sharpeners as well as the Spyderco Sharpmaker more recently.
For waterstones, I'm finding that I like larger stones for kitchen knives. Many stones on Amazon are the smaller stones, so I have to look closer at the details. I really want to try the Naniwa super stones next. I used to sharpen with Arkansas stones, but got away from them.
I've been watching videos here and there and came across videos by Murray Carter. One in particular where he goes about flattening/polishing the secondary edge. I had never heard of that before. I might try on an older kitchen knife to see if I can tell a difference. Might be another one of those "I don't know what I don't know" things, or a "meh, I am just fine with how I used to do it" things.