A potential ‘disadvantage’ from a risk management perspective could be that because your students are using an slippery surface you need to take extra care to make sure that each student is capable of maintaining their balance in a safe way. A matter of increased ‘possible’ risk.
The benefits would be in terms of using any such tool to improve fitness, add variety and provide variety. I use the glide discs with my individual clients.
I hope that this helps.