Nice, I'm an ex-MMF2 user too!
I used clickteam software for ages, all the way back to KnP and TGF, but when I wanted features along the lines of "Zoom in/out", I found that MMF2 lacks the ability to zoom out (and zooming in resulted in pixelly ugliness with no way to blend pixels linearly). Now don't get me wrong, MMF2 is awesome software, I don't hate it, I've grown up with it and learnt all the logic I know now about gaming with it, but I just needed more efficiency, more rapid development, and more standard game-based features (e.g zooming), and C2 gives me that.
The recently added "Replace Object" is a GOD at saving time. I almost needed to sift through loads of events and change an object in each one and edit some actions to refer to the new object, which would have taken hours; but nope, Replace Object. Saved me Hours... Anyway, I find efficiency and rapid development important, otherwise I would just take up C++ lol
I also hated how you would have to copypasta all events to each frame in MMF2, meaning I never completed a game since I would have to fly through all the frames editing something when I notice a bug or just want to add stuff. Sure, there was a global event editor for a project, but iirc it had problems with families, and therefor I couldn't use it.
There are a handful of features I wish are in C2 but my wants are for non-mobile related stuff, like having save/open dialogs and disk access.
I do find that some things aren't clear with C2 such as creating online multiplayer stuff, I'm going to look into that soon but from what I've read in the past, it's not easy to setup (Though I have experience in networking so hopefully it's just not 'easy' if you're inexperienced with networking).
Updates in C2 are awesome! For a small team, they sure do hand out updates frequently and always suprise us with some unexpected crazy awesome feature.
tl;dr C2 is awesome