Yes, they are rather a thorny issue. A nightshade of course, originating from high up in the Andes (cool weather but never freezes) and known throughout Latin America as Naranjilla (little orange) or Lulo especially in Colombia where it is very popular as a refreshing drink. Widely available in the frozen food section along with guanábana, mamey, parcha/maracuyá/passion fruit and so on.

There is a thornless variety but nothing special about it. (there are no 'streakers' in a patch of naranjilla)

The fruit does vary in quality from tasteless to very tasty indeed - but especially as a drink. At it's best it's sweet-acidic and really hits the spot like lemonade, orange or grapefruit.

The tree is short lived. We replace them every few years in Miami. Will likely freeze in zone 7 or so. But getting an early start and using a greenhouse you should be able to fruit 'em.