Maybe it's just that Homebrew turned me off right away. Back in the bad old days, when the Python 2/3 split was more serious than it is now, I had a heck of a time trying to get pandas and scipy running with Homebrew. I haven't given it a try lately so perhaps things are better now.
(I am probably also the kind of person where all the hectoring the Homebrew docs would do about installing to /usr/local eventually got on my nerves ... )
That being said, I don't use MacPorts versions of things like TeX or Ruby (I prefer MacTeX and plain old rvm).