I like sliding glass doors when safety is a necessity (or for flighty animals etc).

I don't use them, as it is no concern for any animals I keep. A bite from my biggest carpet python would suck, but the conveniences of swing doors for cleaning and cage access are wonderful for my situation.

+1 on animal plastics for cages. That's what I use. I've been thinking of trying boaphile lately, they make some fantastic products as well.