The thing the fascinated me about the Holodoc from the beginning was the fact that he was trapped in sickbay (except of course to got to the holodeck). If anyone needed medical assistance anywhere else on Voyager, or on another ship, or on the surface of a planet, he could be of little help, because of his confinement. This was one of the character's defining elements for me. When he got hold of the mobile emitter (and very early in the series' run, might I add), he seemed to become just another "I must explore my humanity" Trek trope. I enjoyed the character when the series was in first run---and it goes without saying that Picardo's a brilliant actor---but in retrospect, I think they screwed the pooch with that mobile emitter thingie. The 'Doc lost a lot of his pathos, IMO.