After maybe a dozen years with Construct, I'm starting on my first large Construct 3 game. I've always used the default theme for my little prototypes, but I recently switched to DARCSS and it almost feels like I'm using a new development tool!
This dark, more modern, theme makes me feel more like a real game developer. (Which is a very strange comment from a 63 year old who has been a professional game designer since he graduated from College.)
This is a huge exaggeration, but the default theme almost makes me feel like I'm using something like Scratch, where DARCSS makes me feel like I'm working in Unity or some other more professional tool. It's been two weeks and the feeling I get when using it still hasn't worn off!
NOTE: To be fair, DARCSS has a few issues. My biggest hassle is that windowed features, like the sprite editor, are nearly the same color as the background. On the plus side, it's more compact so I can see more of my code without having to scroll!