* split-objects to create much smaller binaries. In cabal it's a single line in its global config file.

* Using my already available GHC builds, because stack's GHC builds do not work everywhere, not even across all Linux distros. If I have a musl-based Linux distro, FreeBSD, or Solaris it'll be a problem. Also, there are many users who prefer to use other builds than those downloaded via stack. This happens even if there is already the right GHC in PATH by default.

* I like cabal's new new-foo features and project file support.

* Not bailing out if I open a random .hs file where there's no associated stack config. In a sibling comment Chris says he wants it to work automagically, but then it should create a global stack file, which he says will be used if available.

* Offline mode.

* I will find more stuff I miss, once I have used stack more.