I started using this app at v2. Like all ConceptDraw, the underlying concept is well executed, but the cross platform nature of the app does show up at the UI.
This version 3 is however a major leap forward in UI goodness (and I keep underestimating how important that is to me).
One killer feature that kept me with CD Project, in v2, is that a Project file can be a small bundle of projects, each of which can be represented in a all encompassing project, but which keeps tracking subprojects clean. The big plus with CD is that activities from different projects in the bundle can be linked to each other in the encompassing project. Difficult to explain, but unique for this program as far as I know.
Unfortunately the upgrade to v3 has temporarily disabled this feature, but CS Odessa ensured me it will return in an update.
Responsive support, too, especially on their forum.