I asked a friend very knowledgeable in fruit trees, which is the "Pickering" of bananas? Meaning a disease resistant, productive (decent size), and reasonable tasting banana. He suggested the FHIA 17 banana. Thoughts?
All the FHIA series bananas have some disease resistance, so they are good in that regard. FHIA-17 is a good producer of good sized fruits. The flavor is very similar to a Cavendish banana you'd buy in the supermarket, except that it gets really strongly flavored when over ripe (and not in a good way, to me at least). Personally, I'd choose FHIA-18 or FHIA-01 (Goldfinger) over FHIA-17. FHIA-01 and FHIA-18 are siblings and very similar, but some folks like the flavor of FHIA-18 a little better. They both have a hint of tartness, which I really enjoy, which comes from their female parent Dwarf Brazilian (Prata Ana).
The size of the bunches and the individual fruits of bananas depend on environmental conditions and cultural practices, but those three FHIA varieties can be just as big and nearly as productive as healthy Cavendish banana plants, which pretty much set the standard for productivity and fruit size in dessert (non-"plantain") bananas. When there's heavy disease pressure, they will be more productive than Cavendish varieties.
Personally, I wouldn't be without Dwarf Brazilian. It's at the top of my list for flavor and is a very tough plant. The main knock against it is that it's not terribly productive, in that the bunches aren't huge and the flowering cycle isn't real fast.
For absolutely reliable, high quantity fruit production, it is hard to beat the "Namwah" (Pisang Awak) varieties (Dwarf Namwah and the plants usually sold as "Misi Luki" and "Ice Cream" in the US). They are relatively disease resistant and also handle cold and dry conditions well. Some people really like their flavor, some people think the flavor is just OK, and others dislike it. They definitely have a different flavor (very sweet and with apple cider overtones) and especially a different texture (very dense) than your run of the mill Cavendish from the market. If eaten before they are really ripe (they need some black on the peel and no green), they are very starchy and not so great.
A warning: there are hundreds of banana varieties and getting one my lead you down the path of banana obsession. I know it did me. My small yard is full of them now!