my input:
1. Self promote your game. If you work in the dark for months/years and barely show your product then no one will know about it
2. Sole bad performance I ever had with C2 was my own damn fault for not knowing how to properly use it
3. Oh, speaking of performance, also nw but that was fixed and it was out of Scirra's control
4. Community is very helpful. Have some experience with other communities and I've been advancing faster here
5. Is not because C2 is easier to use that you don't need game logic and a deep understanding, easier to use but easier to mess up things as well
So far, I can say that every design idea I had for my game I've been able to do it without losing performance. is not always easy but C2 is in overall a really good engine