Screaming or non-screaming faces?
 

I have heard this argument so many times before...I prefer a non-screaming face as it makes it harder to display in a normal position IMHO.

I think a variety of faces are good, so I like both personally. I do understand what you mean about the displays though.

I'm not really into screaming faces. A nice "I'm gonna kick your @$$" face is cool though.

The thing with screaming faces, they demand an action pose (or a screaming "NOOOOOO!" at the heavens pose). A neutral face or a grim determination / going to beat you down face generally would look better.

Of course, if you had optional heads, so you could choose the expression, that would be the ideal solution.

I agree with Sol. Changeable heads would be the way I would go with it.