John,
I use moss for all of my colubrids. I started with it a long time ago when I started breeding snakes, and have had great success so I just never bothered to change. I like that the substrate can be covering most of the clutch without smothering the eggs - especially when you get those multi-layer stacks that are stuck together. This seems to give me a great humidity consistency throughout. Also, the acidity may help retard fungal/bacterial growth. And it is soft and just seems more "natural" when the babies hatch.

Bryan

-----
Last night I was laying in bed looking up at the stars in the sky and I thought to myself, "Where the hell is my ceiling?"