Some of the previous reviews are a little unfair so wanted to give you my positive experience.
Pickup from hotel was more or less on time (15 minutes late, which is so standard for Costa Rican transport I think this qualifies as being on-time!).
Shuttle bus (not Jeep, do not expect a Jeep, but a comfortable shuttle bus with A/C and other travellers) was totally fine. Driver stop[ed at a nice viewpoint as we were making good time.
There was a bit of waiting around for our actual Boat to arrive and set off (30-45 mins) but whatever, each boat was eventually filled with a bunch of shuttles coming from different places so there was of course a bit of delay.
Boat was pleasant. Great views, smooth ride.
We were directed to a new driver when coming off the bus, were we gave our hotel and we were delivered to our new place. This bus had some dodgy wheel issues... but they were resolved and we got there fine lol. (Whole trip taking about maybe 4hr door to door).
All in all. Totally happy. Bring plenty of snacks, bring drinks, bring a book if you're not content with just looking out the shuttle window at the interesting sights. Do not be in a rush and set your expectations low. This is shared CR travel, it isn't supposed to be luxury, it's supposed to get you from A/B in a budget way and there's lots of moving parts. Just enjoy the ride. See pics 🙂