Still following the development closely, and haven't subbed yet but will do so shortly i think, to show my support.
Some of the things I'm missing at the moment to be able to move over completely.
1. Chrome or C3 support stylus input. Or be able to run C3 in Edge. As I'm mainly using touch & stylus on my Surface Pro 4 to create games, this have to work. I refuse to sit at a desk in my spare time to make games, I do that 8 hours per day at work already. This works well in C2 at the moment.
2. Downloadable app - As TheRealDannyyy mentioned file handling in C3 web version i don't really like, but not a biggie. I could use Web Version if ..... #1 was fixed.
3. Some plugins converted to .c3addon - Not THAT important, but very helpful, for some features.
I really hope to be able to start using C3, but as long as #1 is not fixed, I can't even consider moving over completely yet.