Another vote here for the Pentax-supplied Digital Camera Utility.
The earlier versions were rather cryptic and unintuitive, but the current release, v5.9.2, has several significant improvements "under the hood", even though it looks much the same on the surface.
From my perspective, the main advantage to DCU is that it "speaks the same language" as the camera, so if you regularly need to apply +3 "whatever" in DCU, simply set the camera to use +3 "whatever" by default (or save it in a User Mode, if you have that facility), and it'll do it for you
Having tried DCU, if you don't like it, fair enough, but at least give it a try