I've been doing Hopping Halves on stage for years. I even used to use the half-dollar set, and it
always worked just fine.
For a very big room, I suppose you might need IMAG, but honestly,
IMAG may not even be strictly necessary in a large theater, assuming you know how to display the
coins well.
Despite a lot of conventional wisdom to the contrary, I've never had a problem
with anyone seeing what is going on, because I perform at chest level, take my time, and really make
sure everyone sees. It's a great way to come down into the crowd and give even a large room a "close
up feel."
Having larger coins makes it that much easier — and these are awesome as long as
you don't drop them on the edge! (Lord help you!)
Highly recommended. Worth the cash,
especially as a second-phase show segment to prove that you're a "real sleight of hand wizard." (If
only they knew.)