Racks save space but not really time, or heating $$. At least mine doesn't anyway it runs at about 30% most of the time where my enclosures at 10% or less most of the time.

It doesn't take long to clean a tub but I do them much more often at the very least twice a month but sometimes 3 or 4 times. It takes me 15-20 min a tub to empty it wash it out disenfect it and do the top of its compartment (that is a real pain...). It takes me 30-40 min to do an enclosure and I do that when it is dirty. It usually is about once a month or once every two months. Not really a bit time saver space saver is different. I'll move all my animals out of the rack when I get the rest (if I ever do...) of the reno done.