I have taken both several times. the Seajets WorldChampion Jet (and other Seajets) and Blue Star (lot of Blue Star).
I take a Seajets when I have no choice.
It's expensive, uncomfortable, it doesn't even look like a boat, the World Champion Jet has a sort of large outdoor terrace without comfort (no seats) and very windy. Most passengers sitting in this giant airplane cabin are just waiting for one thing: for the trip to end and for them to get out.
The Blue Star is like a mini cruise, you can walk on all the decks, there are plenty of shaded outdoor spaces with tables and chairs. You can sit there with your friends, play cards, eat, drink, enjoying the view, go greet the captain, and return to the interior lounges if you get tired of being outside.