I've been running Repetier-Host and firmware on mine just fine. I've run Pronterface and Marlin equally as well. They are both open source so you can download and try them both. They are easy to install on the Mac as you don't have to mess around with drivers for the ports. Repetier for the Mac is some versions behind the PC program. Not sure if it makes much of a difference or not. Flashing the firmware takes some practice. Repetier is nice because you can make lots of settings changes in the EEPROM so you don't have to keep flashing every time you want to make a small tweak to your calibration.
Cheers,
KDog