I already have ghc-7.6.3 installed and up to date cabal. What do I get by installing haskell-platform that I don't have right now? AFAIU Haskell Platform is just a vetted list of packages bundled with GHC?
There's also a few other small tweeks, at least over building ghc from source. But the tweeks don't matter unless you're doing relatively unusual stuff (like trying to ffi out avx simd enabled c codes :-) ). (Which will be easier do do with any ghc in a week or so once some tool hacking I'm doing is done)
yes, in this case there is no need to do anything. The Haskell Platform is vetted packages + an easy way to get it all installed (which can be slightly tricky otherwise).
I dunno if it'll get you anything, but it eases things a lot for me running a tech team on Haskell. It's much easier to get people on board with GHC 7.6 for instance now.