The old trick that people used to use was to put Surinam cherries in the refrigerator for a couple of hours after picking. It would eliminate or greatly reduce any unpleasant resinous taste.
Surinam cherries are variable in taste from plant to plant. There are new varieties such as Zill Dark which have been bred to be quite sweet with no resin, basically like a cherry. But, that cherry taste is not universal. One of my Surinam cherries fruited this Spring; it is a four-year-old seedling descended from a much older, non-Zill-developed plant. The fruit ripened to a bright orange color, and the taste was unique, to say the least, as if someone had mixed together an orange with a bell pepper. With such an interesting flavor combination, I'm not sure I would want to eat them everyday, but at the same time, I'll be glad to eat a few when they're available.