Hey! You completely left out paper clay! I've tried it and have to say apart from that I have only tried water based clay. I like paper clay better though mainly because it is somewhat self supporting and it is easy to control hardness by mixing water to it. Also... You can make it permanent as long as it doesn't get wet, and as long as you don't paint it, it seems to not matter how long it has been laying around you can always reuse dried clay by simply adding water to it again. I'm just beginning and find t cool because if I complexity mess it up I just soak it over a night and restart.