You're right, it's more of a fun thing than a necessity. Right now it has two Brazilian Raintrees in it. They lose their leaves here in winter, because they don't like going below 50 or so, and we get down into the low 40's. Because of this, they seem to lose a whole growing season, as well as twig dieback. Having seen the BRTs in Florida and how healthy they look, I can see that just a little boost of temp and humidity will help them here.
There are also four azaleas. That's an experiment, because I see that azaleas here are often grown in greenhouses, and I'm guessing that they like higher humidity too (being understory shrubs) So far they seem really happy, but it's early yet.
One Dawn Redwood, which will stay here in summer to keep the humidity up, but will probably winter outside for that little extra coldness.
The mames, because otherwise they want to be watered every twenty minutes. A couple of sickly houseplants (our house has very deep eaves so the rooms never get very much sun) and a moss tray. Also a few root cuttings, again for humidity and warmth.
And when it rains next, I want to sit out there and watch the rain as it flows down the sides. Like being in a big bubble.
Joanie