We all know that in Doctor Who, every so often the Doc "regenerates" into a different form and we get a new actor. In VOY, Robert Picardo faithfully & skillfully played the ship's Doc from beginning to end. No hate for that. Just as a purely hypothetical question, if Picardo had wanted to move on and quit VOY, could you have accepted another EMH Doctor - even several EMH Doctors over the course of the show? With VOY's technobabble, it wouldn't be hard to conceive of a reason: "The Doctor's matrix has become unstable, and we need to reinitialize his program. Parts of the Doctor will remain, but even things like his appearance and personality subroutines might be affected. It might happen repeatedly over the course of years, in fact. The program was made only for emergencies, and this is the result of overuse way beyond its original design." Throughout VOY, the Doctor changed his appearance several times for several different reasons, and it demonstrated that it was a simple process for him to do it. In DS9, Dax presented a special set of situations that involved previous lovers and all kinds of nuances that got explored to varying degrees. A similar concept could've been used with this - if the circumstances had required it. Again, Picardo did a fine job, this is just a hypothetical for fun. Piggybacking on thread "The Worf Effect," who would you have put in the Doctor's role if a "regeneration" were required? Not just your favorite Trek character, but what species or other categories would you draw from for additional interesting stories from Sickbay? P.S. This show had a whole lot of Roberts on it!