FWIW, the only time I use a Drum Map is when I want a single MIDI clip/track that triggers multiple synths; e.g., Kick from AD, snare from SD, cymbals from BFD Eco, etc. The Drum Map literally "maps" each PRV note to the desired synth and MIDI note number. It may not be the most intuitive tool in SONAR, but it's pretty cool for what it does.
Years ago someone also had an example of doing this for something other than drums, but unfortunately I don't recall the details.