Just started container gardening for the first time this year, so most of my plants are in 6" pots. The wire shelves included hold almost 70 of those with room to spare. If your pots are ceramic or bigger than that, you may want to purchase stronger shelving. If you have to do that, I still believe this is a good buy.
Set up was very easy. My husband and I did it in a couple of hours. Don't look at the last steps and get overwhelmed. Just start on step one, building up the frame, and it should make sense. Frame is anodized aluminum and joints are plastic, so I recommend a plastic or rubber mallet to make the connections tight. You don't need any other tools. One person could put this together, but two people really make it easier and helps with the instructions. Also, two to put on the cover is nice.
I'm 5'5" and my husband is 5'8". I can walk thru the door opening fine and my husband needs to duck a tiny bit. Inside, there is plenty of room to stand and move around, even for both of us at the same time. He is avg size, I'm on the low end of plus sized.
The mesh windows are great for ventilation. We also leave the door rolled up on warmer days. We live at a pretty high altitude in the Colorado mountains, so I can't speak to high humidity or very high heat conditions. Our low humidity necessitates watering, even inside the greenhouse, every 2-3 days in the small pots.
Last but not least, we have had several heavy rain and high wind (30 mph+ gust) thunderstorms since getting this item. With the anchor kit that comes with it, that little house held fast in the storms. We also had pea sized hail once, but I would worry if it got any bigger and/or lasted more than a few minutes.
If we ever need more space, I'd buy another one of these in a heartbeat. Happy gardening!