website: nitpick alternative installation methods

website/source/docs/installation.html.markdown

@@ -53,13 +53,17 @@ Otherwise, Packer is installed and you're ready to go!
 
 ## Alternative Installation Methods
 
-While the binary packages is the only official method of installation, there
-are alternatives available.
+Installation from binary packages is currently the only officially supported
+installation method. The binary packages are guaranteed to be the latest
+available version and match the proper checksums. However, in addition to
+the official binaries, there are other unofficial 3rd party methods of
+installation managed by the Packer community:
 
 ### Homebrew
 
 If you're using OS X and [Homebrew](http://brew.sh), you can install Packer by
-adding the `binary` tap:
+adding the `binary` tap. Remember that this is updated by a 3rd party, so
+it may not be the latest available version.
 
 ```
 $ brew tap homebrew/binary