Corns have different temp requirements so it likely does not matter for it. It depends on the temp of your room tanks have more heating options for dealing with ambient air temps if your room is cool. Tubs basically have one uth or two. Two would need two T-stats in a cool variable temp room (typical home conditions) and ideally a fail safe t-stat as the total bottom would be covered. Tanks you can use ches and lamp systems that can be controlled with distance as well. Tanks also do better with on off types with direct heat (stuck directly to the bottom heat sources) in cool rooms (swing due to response times and heat loss) Tubs under this type of condition can shift really fast with on off there is no thermal mass to regulate the swings so I'd suggest strongly under these conditions a Proportional t-stat. that amps up the cost again. Tubs handle humidity better but heat is more important.