Croatia's ferries run the length of the Dalmatian coast, and the three crossings bookable here cover both kinds of journey it offers: Split to Hvar in an hour each way, and Dubrovnik to Hvar in four. Most services leave from the main coastal cities — Split and Dubrovnik in the south, Rijeka and Pula further north. The gap between one hour and four to the same island is what makes Split the practical base for Hvar.
The decision that matters is the vessel, because on several routes you are choosing between two different products rather than two operators. A fast catamaran carries passengers only; a classic car ferry is slower and takes vehicles. If you have a hire car that is not a preference but a constraint — the catamaran cannot take it, and the ferry that can runs to a different timetable and sometimes from a different berth.
Tickets come through the aggregators rather than direct from the operators. Direct Ferries, Bookaway and Ferryhopper each list several companies on the same route, which is how you see the catamaran and the car ferry side by side instead of discovering only one of them.