Outside of Room Requirements, Is there Any Reason to Use Better Beds?

I was laboring under the false assumption that the tiers of beds had progressively faster sleep refill times, but rereading the descriptions made me realize that they have faster MANA refill times. Which is. Really pointless past early game since you can just spam mana lanterns wherever your heart desires.

Am I missing something? Is there some benefit to Fancy/Covered Beds in a House Commons, or can I use Plain Beds and fit waaaaaay more students in there?