Guinea eggs hatch much faster than chicken eggs in ideal conditions. In my brinsea they hatch so fast many times I never know they pipped. My sportsman does t do as well, but they are still faster than chickens & USUALLY they all hatch at once. But with pullet size eggs things have been off. I really want a brinsea cabinet, but that price tag keeps me away! Maybe next season we may sell the others & then get the brinsea cabinet, it wouldn't feel like it cost as much then!