ZOO is one of the best CCK for Joomla. The free version is fully functional and you can build a great website without restriction. Obviously, ZOO runs perfectly into a YOOtheme template and especially with WidgetKit. The component requires a learning time. Some features could be improved, but luckily there are people like ZOOLanders, HerdBoy, YOOnique and I offering these improvements.
Again great component as long as you NEVER need support.
Keeping working hard YOO, I appreciate it.