You're right about the factory ballast, it's very nice and rideable with just the PureVert tanks full. If you want a monster wake though, we experimented a lot and just don't bother putting any more weight in the rear, add it only to the center and bow and it gets just huge.
It's a nice boat, but we decided to go a little smaller and cheaper so we now have an '02 Wakesetter VLX. The Calabria is still for sale though so if anyone is looking for a deal, it will probably come in around $47,000 U.S. at today's exchange rates.