Here's my two cents: The root mass doesn't have to be huge in order to support the size that most indoor growers need their plants to reach. Therefore buckets work just fine. Personally I use three gallon pots, and set them on 4x4 trays to catch the runoff.

Also as others have said it is pretty crucial if you have a confined space to be able to shuffle the plants around in order to leaf them and do other occasional maintenance, and cleanup after a round is a breeze, you can just dump the pots into trash bags.

I guess maybe it would work with a smaller setup, but the plants do just fine in 3 or 5 gallon pots at heights of 3-5 feet, and i can't imagine why you'd want to go bigger than that under lights, as the lower branches won't produce much weight and will take away energy from the top colas, therefore creating a headache for you upon harvest when you have to trim those small buds from the bottom and the yield there won't be worth it.

I would never grow in anything but containers but if you do, let me know how it goes.

Maxx