I have flown into West Palm Beach (PBI) twice and made the trip to Vero. It's an easy drive and less than 2 hours away. Orlando (MCO) is about 1 1/2 hours away. Not much difference between the 2. I found better fares into PBI on Song and Jet Blue than flying into Orlando. In West Palm you have to take a bus to the rental car but route 95 is right there. Just go north. The rental agencies all have printed directions to Disney's Vero Beach Resort.
For my future trips to Vero I'll check airfares and see where the better deal is, Orlando or West Palm and pick one of these. The drive is just about the same. On our prior trip we flew into West Palm and out of Orlando to go to Boston. We ended up saving a lot this way.