Cresteds are great! They are pretty calm. Especially after they get use to you. I have never been bitten by one. I have been pooped on by one, though. They can be a little jumpy until they get comfortable with you. I have been told that if they bite it feels like velcro. Whatever that means.
Cresteds are great geckos for their low maintenance and ability to tame down. They can bite, though. I wouldn't say it feels like velcro... whatever that means? ...but more like a soft pinch from a child. They don't have teeth, per se, but hard ridges in their jaws so it doesn't "hurt" when they tag you. And there's really no fear of them biting unless you don't put their food down fast enough or you are just all out "pestering" them... waking them when they'd rather sleep, etc. Some will squeak or bark at you when annoyed, but my L'il Abner just all out bites me for being slow with dinner.
Hatchlings can be jumpy and fast, but with frequent handling... if you prefer a "tame" gecko... will calm them down some. I only handle mine for maintenance and health checks, so a couple or three times a month, but they are fairly calm during this. It doesn't take much.