There are two commonly grown red bananas.
Cuban Red (a.k.a. Red Cuban), which is among the tallest of all bananas (often over 30 feet; occasionally approaching 40 feet), with small clusters of small, dark red-skinned bananas.
Jamaican Red -- a mutation of Cuban Red. Semi-dwarf (seldom more than 10 feet tall), with much larger clusters of much larger fruit. This is the one you sometimes see in the grocery stores.
Unfortunately those names sometimes get switched around, so it's best to ask if the tree is tall-growing or semi-dwarf. As with all banana sport pairs, where the mutant form is a shorter version of the taller parent, it seems always to be the case that the shorter one will bear more and larger fruit. I don't know of an exception to that rule.
