I don't know how many times I've read in all these forums about people having CG problems.  Many times they don't understand CG and what it actually does.  The Vennessa contraption will show them. 

Sure, it isn't something you'll use every time you fly a model, but understanding why something works is half the fun of making it work.  For me anyway.

So for me, I thought it pretty interesting when I saw it used for the first time this past weekend.  To each his/her own.