as most of you know, I am growing in 5 gallon pots this year...I think they are about 12" (~35cm)...what I have observed is that the plants that have grown roots out of the bottom of the containers into the soil are at least twice as large with at least twice as much production as the ones that are constrained to being in the pots...it all depends on how long your growing season is...for instance...I started my "contest" naga morich plants in January, transplanted them to 5 gallon pots in March and they were totally rootbound by the end of August...the pots I put them in did not allow the roots to grow out of the bottoms...with the other 5 gallon containers I used (cheap black nursery pots), the roots grew into the ground out of the bottom of the containers and are much healthier...
I have one plant in a 7 gallon container (orange Hab) and it is just now getting root bound but has produced well over a 1,000 pods this year...
I will stop rambling and just say in my opinion, the larger the pot the better for superhots...smaller pots can be used for smaller plants like thais of course..