I played around with Dark GDK a bit and also finished a small game.
Hooking up Newton for it is not a real problem if you know how to
I also dropped my Wiimote code into my Dark GDK project and had it running within an hour.

However I don't think it's really similar to Lite-C.
Ok, you program in C++, so the syntax is quite similar to Lite-C, that is true, but how things work is a bit different.
Especially the object index system is a different approach than the object pointer system (ENTITY*) of A7/Lite-C.
Also collision and particles are done differently.
A real pain was importing objects, as every tool seems to create different .x files.
I finally ended up writing a class for importing Acknex MDL5 files

I didn't really feel comfortable with Dark GDK as I'm used to Lite-C/A7 a lot, but you can create things FAST with it - and the tutorials are good enough to get you started. The manual lacks information, though.