If i'm not mistaken, these are 2 different parks.... which would you recommend?

Some people do both; we only did Monteverde and were very happy with our choice. We saw a quetzal, howlers, coatis, and lots of birds and insects. If you get a chance, do the night hike at Hidden Valley. We loved it and saw a porcupine, fox, raccoon, agouti, sloth, etc. I thought the night hike would be kind of creepy, but it was really fun!

These are definitely two different parks located on either side of the town of Santa Elena. We hiked both, found Santa Elena to be much less crowded than MV since it's a little out of the way. At MV we saw quetzals, howler monkeys, coati, toucanets, hummingbirds, tarantula and really enjoyed our tour guide. For whatever reason, he didn't think we should go to Santa Elena, but we liked it very much. Fewer people, saw quetzals, coati, and even a three wattled bellbird, got a surprise when a peccarie came crashing through the woods towards us. Our guide told us that was "Charlie, the wild pig" who loved people and had grown up there after being abandoned as a baby. I think Santa Elena is at a higher elevation and I thought the trails we took were steeper than the ones at MV. If you have time, do both!

MV park is more visited (and more expensive) than SE park. If you are planning to hanging bridges/ zip line/ canopy tours (Selvatura), then SE park is adjoining to these other attractions.
SE township is more lively for evening - so if you do end up staying in its sorrounds, SE park may not be as "out-of-the-way" as you might think.

I was shocked at how touristy Santa Elena was. I thought it would be rather quiet and out of the way. A couple on our Jeep Boat Jeep didn't have a place to stay yet, so they asked to be dumped out in the downtown area, and immediately they were surrounded by a lot of loud and very persistent people saying "stay here" and "take this tour" etc. It reminded me of Mexico. I had never seen anything like that in CR before.

If you have time, and you're interested, I would do both too. We just ran out of time.

The ecosystems vary between these two parks, but not greatly so. Both are worth doing.

The important thing to know is that the guides need special credentials to guide in the Monteverde Reserve. So the "uncredentialed" guides that are trying to sell their services are going to tell you that the Monteverde Reserve is overcrowded, and not worth doing. Don't let them talk you out of visiting the reserve. I have been going for years, and am not tired of it. It changes with the season, and I see something different every time I go.

Regarding the people meeting the buses? They have gotten a little more aggressive over the last few years. When I first visited Monteverde twenty years ago, there was even a little of this going on back then. But it was usually local families offering a bedroom in their home. It wasn't offensive, it was part of the experience.

These days, most of the backpackers stay in the inexpensive pensions scattered in and near Santa Elena. There are only a few buses per day, and everyone knows the schedules. So the pensions pay small commissions to those who can bring them guests. A few independent guides have found this as a market too. So there are more people greeting the buses.

As recently as just a few years ago, downtown Santa Elena was mostly local shops. Hardware stores, sodas, the bank, supermarket, post office, etc. As tourism has caught on even more, most of the spaces have been rented to tour companies, restaurants, and other tourism related businesses. The businesses that cater to locals have mostly moved to the outskirts.

But the charm of this community is still there. You just have to look a little harder to find it. I was there last week, and still love it.

Hope this helps! Let me know if I can offer more advice.

Warm Regards,
Pat Hewitt
(Travel professional)