If we're just going to Vero, we fly into Melbourne. Airfare is a bit higher, but worth it to us to save time driving from MCO. So nice to be 30 miles away and an easy drive. Melbourne is a nice, small airport with minimal stress.
I think Melbourne is the best little airport anywhere, but unfortunately has limited airlines and usually higher prices. But if you can get something reasonable to MLB, I would definitely fly there.
We flew into West Palm. Could not bring DH that close to WDW and not go there, so we flew to West Palm Beach. About an hour and half drive up to VB. Airfare was also cheaper for me from my area,