I'm glad you say that light is fantastic. The stock headlight on my bike is woefully inadequate. Especially for a nature trail at night (part of my commute).
What kind of bike do you have? I have a Giant Explore E+1 and I wanted something that would effectively be plug and play. And since sourcing out the the correct plug, once I install that onto the wire from the light I'm going to be in business. I'm a handy guy, but personally I really don't want to have to dig into the bikes wiring to connect something else to it. So I'd be very reluctant to get that horn even if it was the same cost as the one I ordered. And it would cost almost 4 times as much as the one I got today. (Converts to $63 Canadian, plus fairly expensive shipping.) Sure it's better, but...
You feel comfortable connecting something non-standard to your bike? You're a better (braver) man than I am.