I am afraid of heights, but decided that this was something that I wanted to do and it was absolutely worth it! It drizzled almost the enitre time, but it was a blast. Our guides were very helpful, informative and took photos and video for us. You have incredible views and you have the option of repelling from one of the trees. I thought I was going to pass out at first, but the rush was incredible and climbing back up through the hollow tree was very cool. The tarzan swing is at the beginning of the trip and for me that was by far the scariest part.
Be prepared to hike and if given the option have them pick you up becuase we drove around for almost an hour trying to find it even with the gps. (gps not so good in Monteverde, just fyi)