The effect?

They are healthy, stress free, eat with consistency and breed

Yes rack do allow for thermal gradient just like a tank does you provide a hot pot and a cool spot.

As far as hides not everyone use them in a rack, personally I offer 1 which is moved around from cool to warm end. (I would rather provide 1 and have it not being used than not providing one and it being needed). Remember that rack offer more security than a tank which is why hides are not always necessary with a that kind of setting (it comes down to observing and knowing your animal.)

Originally Posted by Lateralus_Love
I've also wondered about this. When people post pictures of their setup in a glass tank, occasionally you'll see the comment "That tank is too small for your adult." But, I've seen more pictures of racks/tubs that are, imo, small, for adults. Alot of people have said they just use 41qt tubs for their adults I think? Those seem too small, to me anyway. They seem perfect for my juvies, but for adults... Is there a reason for this?
First I never seen comment such as
That tank is too small for your adult
however I have seen the opposite countless time and for a good reason.

Keep in mind that the footprint of a 41 quarts tub is about the same than a 30 gallons tank, and that BP are ground dwellers they do not require heights.

Also keep in mind that an adult does not require anything larger than a 30 gallons tank.