Although I'm no expert, I personally would avoid the internal route entirely unless a dispatch support/assistant dispatcher position opens up at a major. Who knows how long it will take to get brought over to dispatch once someone is internal. Could be a year or ten years. Going external allows you to diversify your assets and have a shot at every major carrier not named Delta. Plus you get to dispatch while you're on your way to the majors instead of throwing bags or doing some other non-dispatch internal function. Depending on the airline, assistant dispatchers/dispatch support/FSCs have a pretty good shot at moving over internally in a reasonable amount of time, but it's far from guaranteed. Then again, getting to a major from a regional isn't a guarantee either.
