Heat treat and intended use.
I have a couple of Case Tru-Sharp (420HC at 56 Rc) and find when I sharpen them too thin, they tend to roll an edge more easily than Buck's 420HC (58 Rc, give or take).
What I'm doing with a knife has an effect on what angle I'll shoot for. The rougher the work, the steeper the angle. For EDC and kitchen use, I use a 17 deg/side back bevel with a convexed 20 deg/side micro bevel at the apex.
David: I would be curious to learn what technique you use to establish a shallower micro bevel instead of a more obtuse one. Rounded belt?