I've eaten all of those that you mentioned. Jostas are pretty good, but I personally prefer gooseberries and blackcurrents (the two plants that were hybridized to come up with Jostas).
Goumis are excellent. I imagine they load up, but the ones we have right now are still small so I'll have to wait and see.
Autumn olive in full sun tends to load up like crazy.
Here's a caution with goumi and autumn olive: if you want to grow autumn olive make sure you get SELECTED VARIETIES (garnet, cardinal, ruby, etc.). The seedlings are super astringent (in almost all cases). Goumis, however, tend to come much better from seed. The available goumi varieties are a sure bet, but my understanding is that you can probably get away with just doing seedlings for these.
Aronias are great. If you eat them underripe they will be super astringent. However, I've found that the juice makes a nice additive to pear sauce and other preserves. I even had a friend bring a five gallon
bucket of them into an ice cream shop where they made "Rasp-aronia ice cream." Who wouldn't eat that??? Note that these are like
deer candy. Also, I don't think there is much difference between the aronia selections available, but I tried a seedling for the first time this fall and it wasn't very good, so probably best to stick to a selection.
Other berry-like fruits to consider: red currants, blueberries, blue and black elderberries, white currants, Cornelian cherries, Chilean guavas (Ugni molinae), and mulberries.
Also, if you're interested in the Elaeagnaceae, look into Elaeagnus x ebbingei. Although I've never tried it, I've heard that it is excellent. I believe it requires Elaeagnus pungens as a pollenator.
Good luck!