We took the ferry on our first time to SB. It was just after the crash that killed 19 on approach to SBH and that had a lot to do with our decision.
The ferry was at sunset from Marigot. Had to taxi 30-40 minutes to the dock. The ferry took well over an hour in very rough seas, in darkness. People turned green and some were puking. Got into Gustavia and within 10 minutes everyone was picked up and gone. No taxies, no transportation to the hotel. (this was before international cell phone coverage) I had incorrectly assumed a taxi would be available.

I believe taxi service has since improved. We took a Winair flight back to SXM and have never used the ferry in 10 trips back. We use St Barts Commuter.