I have different machines running different linux distros, so I'm familiar with all the popular package managers (apt-get, yum, pacman), and I must say, Homebrew is really my favorite.
Binary packages are a wonderful thing and a package manager that doesn't support them out of the box isn't a usable solution for the things I do.
Homebrew also doesn't manage OS X itself, which is something I really prefer about apt-get.
The benefit of apt-get source is being able to read the correct version of the source code of any part of the operating system to debug a problem, not necessarily building from source.
Wrong. Homebrew has so-called "bottled" binaries that get "poured in" unless you tell it to build from source or use a flag mandating a custom build.
I'm using the former and it works pretty well for me. Though I wish either of those would use apt-get like Fink did.
It's exactly the same the other way around for e.g. audio and video editing on OS X vs. other platforms.
If I were forced to use OSX or someone gave me an OSX machine I think I would get along fine and be productive, though. I can actually get along fine in Windows, too, but it is somewhat frustrating and slower for me to get things done.
Not that Linux is perfect, but I'm used to it.