Gantt chart - all these posts going back 3 years!! I am assuming the Mac version is "acquired" not a Mindjet product. It is so different and that is a shame. I upgraded my iMindmap version to 7.1 so I had a Gantt chart available on my Mac.
Mac is my main platform and I am using iMindmap 7 in the main. I run Mindjet under Parallels as their Mac product is only now on a level with way cheaper less functional products. I teach mind mapping and give students overviews of available products as part of my courses. Mindjet for Mac scores 4/10.