Storm from Pyroworx is a fantastic four-part compound. I really can't praise it enough. The guys at Pyroworx designed it to fire in a stunning firing pattern with a perfect mixture of effects.
I honestly feel like a broken record with this; the way this masterpiece fires is perfect down to the last shot. A gorgeous low-noise fan grabs the audience's attention before unleashing a noisy, relentless crackle.
The quality here is second to none, and with Storm lasting almost a minute and a half, you'd be hard-pressed to find a more complete Compound cake on the market today.