Hey man, been following your work on here, some really astounding stuff :-D
So far, I love it. Absolutely no compiling involved, everything is realtime, you can switch straight to the game with one click (I think you can do this in UE3 too). It accepts any image type for materials, as opposed to the Source Engine which needed conversion to VTF file format and even then the image dimensions were very specific.
It doesn't really have much in the way of brushes though, I think the CryEngine is more targeted towards using static meshes produced in other 3D modelling apps, but that's cool.
Also, the ability to apply any material to any model, and set the reflection, gloss, bumpmap etc straight from the editor blows my mind. The Source Engine really has fell behind.
But yeah, to answer your question, I'm VERY impressed so far :-)