I have used CBC 3 times. I buy the maximum quantity that will fit in the shipping box. Though they are cheaper on shipping and a bit less on product, I prefer Big Cheese and Perfect Prey when they have my sizes on hand. I have also experienced better sizing with BC and PP.
With CBC, sizing is all over the map. One pack of Larges will be perfect, then another one will be half full with mediums. Then a pack of mediums may have a large or two and 4-5 smalls mixed in as well. . Though I have snakes that will eat the misplaced sizes, it throws off my planning for my next shipment.