I left MacPorts because the political infighting between package maintainers often left ports hopelessly out of date.
I also ran into a number of broken ports. I had used Fink, but I ran into issues with its packaging too. So, when I heard about Homebrew, I decided to try it. It's been pretty decent for me so I've stuck with it. The only major issue I've had has been related to Octave, but that's been a problem for MacPorts too as the OS X version isn't as up to date as the Linux version at times.