Only issue is condensation inside the tent when it's cold outside (water drips from roof). That's a RTT issue though, not a Tuff Stuff flaw. There are two side vents, but they aren't enough to prevent condensation when you zip up everything. You need to leave a window slightly unzipped in the cold nights.
Make sure you get the optional condensation mat. Otherwise, condensation (water) will soak the bottom of your mattress.
The condensation mat costs extra, and it comes in two pieces. Not a fan. It tears easily and one side will never stay in place when closing the tent. I think the one piece Tepui condensation mat is way better.