I know I’m a bit late for the party, but I just upgraded from 4.1 to 4.4 and for me the biggest and most important change was the UFBX integration. I have many 3d models from different sources, and the amout of additional tools I had to use for my models to import correctly was insane. For some of them I even had to use Unity GLTF converter, and don’t even get me started on FBX2GLTF.
Suffice to say, all the problematic models I have have imported correctly now (directly from FBX), with animations and everything. This makes my work much easier and increases the possibility of my game eventually seeing the light of day 
Thanks once again and may Godot one day surpass the other engines in popularity.