Just to begin with:
- Chaptering within movies is crippled
- Positioning and resizing of images in 'drop zones' and menus is crippled
- No frame-grabbing of images from videos
- It's almost impossible to add transitions without increasing project duration (often apparently by random amounts - this has to be seen to be believed)
Also, more generally, both programs have work flows that are dumbed down to an incredible degree. Using them is like being trapped in software Idiocracy. What an appalling company Apple has become: rich, abusive towards its users, contemptuous of norms of incremental and logical design.