It can sometimes be heavy, it gets muddy when wet and it may have stuff in it that you don't want in your tank, though I don't worry that much about that. It's mostly the weight and the muddiness.
It does make a difference if you're planning a leopard gecko enclosure or an arboreal gecko enclosure (crested gecko, gargoyle gecko etc). The arboreal geckos won't be spending that much time on the substrate and their enclosure will be a lot wetter. Here are some articles from Gecko Time about habitat and bioactive enclosure for gargoyle geckos and for leopard geckos:
Advanced reptile keeping has turned to naturalistic enclosures to improve quality of life for captive animals, and keepers have naturally expanded to bioactive techniques to keep non-sterile setups healthy. As mainstream awareness rises, more new reptile keepers are curious about making...
This is the second article in this series. The first article is here. Vivarium Construction Enclosure and Hardscape It is important when creating a naturalistic enclosure to provide adequate space. Your plants grow fuller when given more room, and a larger substrate area absorbs waste faster. I...
All bioactive enclosures have the same basic requirements, but the needs of your main inhabitant dictate the ways in which you can support bioactivity. Many people have claimed it impossible to create a bioactive desert terrarium, but let’s not forget that life persists all over the earth, even...
This is the fourth article in this series and part 2 of leopard geckos. Gecko Time readers might recognize this enclosure from a previous leopard gecko bioactive article. What happened? Superworms! Zophobas morio overpopulated and became a smelly nuisance, and the worms escaped through gaps...