Hello,
The following making-of has been made using lots of Synfig for animations, a bit of gimp for drawings clearing/cutting, and kdenlive for audio syncing. Any comment is welcome.
lavraiehistoire.be/le_making_of.html
Audio is in french only by now… pitty for you get nice second-sense-jokes if you are a native 
… but you can get translated subtitles by clicking on the related bottom-right icon.
Features I really liked included particules (for the snow), duplicate (for train tickets), camera widget (for travelling), key-frame based distortion, coloring layer, and many others, so big thanks to all who contributed to synfig!
Berteh.