Shmuelyosef,
For me, drum maps are essential to being able to EASILY edit my drum midi. It is SO much better organized/modifyable to gets your individual instruments properly grouped as they are in a midi drum track rather than scattered about, in the order of a keyboard, and separated by other unused notes. If you happen to want to split a midi drum track to hardware and various plugins (hardware snare, software cymbals, for example), drum maps make it easy to do. Also, since drums are percussive and the note length is irrelevant, the notes are more logically displayed to me in the drum map view. The velocity display is also more sensible in this view than the controller info at the bottom of the pane is for drums (though I think you can turn this part on in a regular midi grid).
Since I always use the vdrums to input my drums and I typically send that back out to the vdrums brain for hearing the sound and usually mixing it in as audio, everything is just automatically setup with my default/custom drum map.
Anyone who doesn't understand some of the benefits of drum maps, please check out the video on my website about the topic. Maybe they do more for you than you originally thought or explored.
HTH