Ive switched back to the lab block alone and it takes them a lot longer to get through the same amount of food. I was filling those hoppers twice a week, Just to copare i would fill that hopper up then dump it onto the top. I now fill it once every 5-6 days. The asfs don't dust as much food because they have to work to get a chunk small enough to get down into the tub. They do shred the crap out of the bedding now though.
I'm going to stick with lab blocks now, the 3 extra bucks per 50# bag is totally worth it