Not only is there a size difference, but the shapes can be different too.
Short and fat. This is high up in a tall tree, so I couldn't get a good photo. But the top banana to the bottom flower tip is 18". The fat flower on the end of it is 8" long.
Long and skinny. This flower clump is 24 inches long, but it is skinny. It is just opening so you won't see any baby bananas yet.
Bananas are really interesting. Having lived most my life on the US east coast, banana trees are still a bit of a novelty. So when I come upon an edible variety new to me, my ears tend to perk up. I used to buy any new one I came upon, collecting a new one even when I didn't have a hole to plant it in. Rather complusive collecting, eh? But after collecting quite a number, I now limit myself to only adding the dwarf types. Those 20'-24' tall ones can be quite intimidating to harvest from. Definitely don't stand under one when you chop that truck........crash- smash! Nothing like having over a 100+ pound banana trunk fall on ya. The older I get, the more appealing those dwarfs get to be.
Not only is harvesting easier and safer from the dwarfs, but tree maintenance is far easier too. As the tree grows, leaves die back. I like to keep those dead leaves trimmed off in order to reduce disease problems and discourage insects and rats. That's really difficult to do on those tall varieties. Yes, give me just dwarfs nowadays.
Of course there are some benefits to growing tall varieties. First, it may produce a banana fruit that you really like. Plus those big boys produce a lot more biomass for turning into compost. When I was chopping and fermenting the trucks for livestock feed, they gave me lots of buckets of trunk chunks. But I'm no longer doing that--- for three reasons. It's time intensive. I have plenty of other feedstock options available. The pigs lost interest in earring it.