Your pc specs are just within the minimum system requirements so you should be able to run Eco fine under lower settings. There are some performance issues that we are still working on + final optimization a bit later after all core systems are in place. Also there are some macs still having major graphic issues from time to time sadly. We working on resolving them but since several of our own macbooks often dont show these issues we would love to get some help from people having these issues, like unity logs and some patience in resolving these issues. one of our primary goals is to support mac's.
So i hope that helps your decision =)