In my opinion, if its not broken-don't fix it. You have to also consider the fact the when running a single incubator, there is the possibility of a malfunction resulting in several clutches of cooked eggs...in the closet, the chances of an extreme change in temperatures is very small, if not impossible...to me the closet is a much safer method to incubate, even if it does mean that incubation takes a month or two longer. I feel that incubators are really the best option for eggs that require much hotter temperatures to hatch. Crested geckos, chameleons etc don't require high temperatures, so in my opinion, they do not really require an incubator.