At first, I was popping the balloons because I was so nervous puncturing the balloon with the needle. Then, I just started doing it to open the routine (makes the kids go nuts!!!). So it is a great climax when you actually perform the trick. I always end with popping the balloon.
It really does look like magic. I am actually somewhat is awe (maybe surprised) when I stick the needle thru the ballon. Good trick, worth the $$$.
Also, get the needle wand that Penguin sells to store your wand it. The needle is sharp and the wand protects it. Plus, it looks classy. And it has another secret function. Worth the $$$ too.

This wand is perfect for holding the needle through balloon. The hole is large enough that the needle easily fits, yet it's small enough that it scrapes most of any excess Vaseline off, keeping your hands relatively grease free.

Looks nice too, although I ONLY use it for storage - I don't actually bring it into play.