High Level TR - I want to focus on writing something so will opt for a shorter TR. Happy to elaborate for anything if interested! Our trip was in the summer, during rainy season
Costa Rica has so many wonderful areas, so the hardest decision was staying in one location (mostly) so that we would be able to enjoy and not be rushed. Arenal/La Fortuna is an amazing option with volcanos, hot springs, adventure, rain forests, wildlife all in one area - the main thing we skipped was the beaches, and we were fine with that. Stopping in La Paz on the way back was also a compromise so we felt like we were getting multiple locations. We also wanted an adventure trip (read: that we couldn't do with toddlers) and that was a main focus.
We ordered food in advance from a number of kosher places in Costa Rica and asked them to deliver to one of the locations. Our driver picked up from that one location. We recommend Menasci for dairy food and Super Kosher for meat.
For our hotel in La Fortuna, we wanted a nice place with a pool, central location, and accommodating with kosher food. We went through a long list of hotels that would fit all the above, and ended up with Noah's Forest by Tifakara. Our compromise was not having hot springs on the property. The hotel and staff went above and beyond to accommodate and was absolutely incredible. I can't recommend this place enough.
We opted out of driving and instead got Ubers/booked ahead for longer rides. Within the La Fortuna/Arenal area, Ubers were plentiful and it was fine. We really missed not having a car on the last day, where Ubers were not available in the La Paz area, and we got into some tough situations. Looking back, we would definitely get a car.
Class 4 rapids - was an amazing experience, 5/5. only thing I'd change is doing it on the way to the airport/La Paz (or on the way there, but on the way back you'll have less stuff) because it's a ton of extra driving the way we did it.
Arenal hike - 3/5. felt like we had to do it but we saw the volcano all trip long, was cloudy during the hike and the whole trip. Nothing crazy but kinda cool.
Mistico - 5/5. Our guide was absolutely incredible and made the trip. He put all the other guides to shame and was showing them a ton of stuff. PM for his number.
horseback riding - 2/5. skip it.
Canyoning - 5+. included Ziplining and rappelling through waterfalls. With Maquique Adventures. The most wonderful experience. Do this if you have only one day!
La Fortuna watefall - 4/5. Pretty cool, and you can't skip it
One of the nights we did Baldi Hot Springs -3.5/5 if you go to the volcano area, you gotta do the hot springs. super chill.
Another night we did the wildlife tour at the Tifakara hotel (sister hotel of Noah's Forest). 4/5.
La Paz - 4.5/5 overall so peaceful when the day guests leave and it's just the Peace Lodge overnight guests. Highly recommend doing the feeding tour (for hotel guests only) where we fed sloths, toucans and hummingbirds. The waterfall hike was great.
Poas Volcan0 - 3/5. Low scores because it was cloudy and we didn't see much, and we got stranded by our Uber so that was really stressful. I'm sure your experience will likely be much more positive
Doka Coffee - 4.5/5 - we had an incredible tour guide from the Peace Lodge hotel that made it an incredible experience.