This type works well as long as you can keep enough air flow. With 3 drawers you would have to keep 2 stages together tho...like dump your tiny hatched babies in with grown mealies (I would worry they would eat them tho lol) plus the added factor of not being able to clean the frass out for a while until they were grown enough...you could clean just before putting them in each time tho.
I also had a bad batch of worms from a store...I had fed lots/many turned to aliens and needed to top up...that killed nearly all of my grown worms
I had to start fresh but only with the grown worms. Due to using seperate bins it had no bearing on my aliens or beetles. Many people farm them all together without any issues too.
with the other type of container you posted http://www.joann.com/joann/catalog/p...DID=xprd408781
I've seen some people use these for putting the aliens each in a seperate space. They don't need to eat but beetles will snack on the aliens so I guess the idea is to avoid that with seperation if you can't check and remove beetles from the aliens each day.