I use macports, but I had never switched away in the first place. My short list of reasons include macports keeping everything tucked neatly away under /opt by default, which means I can blow it away without having to worry about breaking anything else; it manages its own dependencies, so things don't break when system libraries change; and it does binary installs by default and checks shared libraries for breakage when things get upgraded. Generally I find it Just Works, so why change?
As a bit of history, when homebrew first landed, it existed because the author wanted to pass optimization flags to his builds [0], and found the macports build system too complex for this purpose. Homebrew's real strength is the relative transparency of the build system (it is more obvious what will happen when a build launches), which is really a reflection of this initial complaint about macports. At the time, I didn't care about optimization flags and didn't otherwise get a good vibe from the rest of the project, so stuck with macports for the reasons I listed above (less the binary installs, which didn't exist yet). Since then, I've been a bit surprised at how much Homebrew has taken off, but macports has continued to improve as well and I am still very happy with it.
As a bit of history, when homebrew first landed, it existed because the author wanted to pass optimization flags to his builds [0], and found the macports build system too complex for this purpose. Homebrew's real strength is the relative transparency of the build system (it is more obvious what will happen when a build launches), which is really a reflection of this initial complaint about macports. At the time, I didn't care about optimization flags and didn't otherwise get a good vibe from the rest of the project, so stuck with macports for the reasons I listed above (less the binary installs, which didn't exist yet). Since then, I've been a bit surprised at how much Homebrew has taken off, but macports has continued to improve as well and I am still very happy with it.
[0] https://news.ycombinator.com/item?id=1198037