Guess it all comes down to how many you have, i myself have 4 bp's atm, but plans for more. Just waiting on another rack to get here. I mean if you only have a couple of BP's then sure have them in tanks but people that have more than a couple probably dont want that many tanks(i myself dont). Tubs/racks are so much simpler, take less space and easier to clean. I can clean my 4 tubs in my small rack quicker than i could my 1 tank.