Yoga mats stink disgustingly, despite antiseptic wiping (or maybe because of this). My head starts to hurt.
The toilet sink is disproportionately small. It is impossible to wash your hands without getting splashed.
It is convenient that there is an online recording, but it is uncomfortable for more than 4 people to practice.
As for the coaches, you need to know who you're going to see, but it's like everywhere else :)