I have zero personal experience, myself, but am planning to acquire a leachie in the next couple years. I will probably house him in a 24" x 18" x 24" ExoTerra. If he turns out to be truly giant, I would increase the cage size. Some people in the crestie community get a little crazy with housing. The other day I saw someone tell a newbie that you could only house a single crested gecko in a 24" x 18" x 24" cage. I disagree with that sentiment.