Re: [Haskell-cafe] Most Important GHC extensions to learn/use?

On Fri, Jun 1, 2012 at 6:29 AM, wren ng thornton wrote:

   TypeFamilies (aka TFs)        These are really nifty and they're all the rage these days. In        a formal sense they're equivalent to fundeps, but in practice        they're weaker than fundeps.

Is that still true? The reason used to be that we didn't have superclass equalities, but we do have them now since 7.2. The only drawbacks I know of relative to FDs are that it's sometimes more typing, not supported by GeneralizedNewtypeDeriving, and doesn't allow OverlappingInstances (ick).