Tissue cultured bananas are obtained from the "eye" of the corm. Before a pup is formed, it is an "eye", similar in some ways to potatoes. Then they clean that eye, which is actually the meristematic tissue of a tiny banana plant, then place them in several series of growth media to enhance cell division and multiplication, then later on, differentiation to form the plantlets. The plantlets are also grown in series of culture media, usually in test tubes first then unto individual tiny pots and moving to bigger pots. Thus the tissue cultured bananas are called plantlets instead of pups. From one "eye" of the original corm, you can produce several hundred thousand plantlets in just a matter of weeks.
Banana pups are way better if you handle them properly. For one, the pups are already cold hardier than the plantlets. Banana pups develop bigger corms in shorter time than plantlets. The plantlets would take sometimes 5 years or more before they bloom in my yard while a pup in just a couple of years. The very first few bananas that I gave to Benny were tissue cultured plantlets and so it seems that it is never going to fruit, but it will as soon as the corms are of good size.
You can tie a banana pup behind your truck, drag it around the block, and plant it, it will grow. Something that you cannot do with a plantlet. If you break the plantlet in half, it will surely die because it has very little corm for stored energy to grow back during the cool months. You break the pup in half, it is no problem, it will grow just the same.
Lastly, even if you managed to get fruits from a plantlet later, the first bunch would be small because the corms are not yet big, but after the first harvest, it will be no different anymore. The fruit size is proportional to the corm and the size of your stems and the number of pups (fewer pups, the bigger fruits, so remove some of them frequently) when you compare the same cultivar. Thus the more developed the corm is, the more stored energy the banana clump has, the bigger fruits, more reliable producer, also cold hardier. The life of the banana is in their corms. If the corm dies, the banana technically is dead. Each banana plant will die off after blooming, but they are constantly replaced by the pups coming from the corm.
The biggest advantage of plantlets is that you can get them sometimes for just $1 each. It takes longer to care for, so you will have to pot them first, until they grow to about 2 ft high stem before inground. If you plant them in the ground immediately, they would easily die.
Sometimes, the only way to obtain cultivars is by the cheap banana plantlets propagated by tissue culture. For example, when importing banana plants to the US. Tissue cultured plantlets growing in sterile media inside a test tube would easily pass inspection.
The best times to order tissue cultured plantlets from eBay is during April to September. If you order now, and the seller is from Florida, the plantlets will pass through the unheated hubs in Denver, and you'll get damaged plants at this time of the year.
And there are times that tissue cultured cannot be applied to some banana cultivars, like the Ae-ae. That is why the prices remained so high, greater than $100 per pup. When tissue cultured, they revert back to all green, or sometimes pure albino which will die easily. So the only propagation method is by splitting the corms or pups which is time consuming and costly. There are promising leads in this research for propagating Ae Ae.
California Gold is also problematic when tissue cultured. The resulting plants are always mutants which loses their cold hardiness, are either very tall, or very skinny. So the price also is high for the pups.
But whenever you can obtain cultivars of the pups that you want, and economical for you, do it. And for the plantlets, order them starting April. If you can care for your citruses, you will be able to care for the plantlets until they are ready to be planted in the ground, just expect many years before they fruit.
