I'm confused about how to choose between data family and type family. The wiki page on TypeFamilies goes into a lot of detail. Occasionally it informally refers to Haskell's data family as a "type family" in prose, but of course there is also type family in Haskell.
There is a simple example that shows where two versions of code are shown, differing only on whether a data family or a type family is being declared:
-- BAD: f is too ambiguous, due to non-injectivity
-- type family F a
-- OK
data family F a
f :: F a -> F a
f = undefined
g :: F Int -> F Int
g x = f x
type and data here have the same meaning, but the type family version fails to type-check, while the data family version is fine, because data family "creates new types and are therefore injective" (says the wiki page).
My takeaway from all of this is "try data family for simple cases, and, if it isn't powerful enough, then try type family". Which is fine, but I'd like to understand it better. Is there a Venn diagram or a decision tree I can follow to distinguish when to use which?