The pedal is very clean, and has true bypass so it won't interfere with your unmodified signal. The Fuzz is OUT OF THIS WORLD. It has a butter smooth feeling, overtones are present load and clear.
You can dial up some crazy sounds too, some of which would be enjoyed by only a small number people on the planet. However, there is an incredible range of sounds that sits in the palatable domain.
Reliability/Durability:
The box is built for abuse and I trust it. But this is only trust as I have not owned it long enough to say its totally reliable.
Ease of Use:
The Piercing Moose has three controls, Fuzz, Tone, and Level. All are tuned, so placing the pot at a particular setting means that it is well defined. This is as opposed to some pedals where you get it to 1/4 and its as though the thing were already maxed out. The relationships between the Fuzz/Tone and the Level settings are little more involved. e.g. raising the Fuzz adds a bit of level.
Customer Support:
I've talked directly to the maker/designer on the phone, he was really helpful in helping me make a decision. It is a small operation so it is hard to say what will happen when they get swamped.
Overall Rating:
I would buy this pedal over and over. It it responds to many nuances of my playing, it changes character as a roll the volume on the guitar off. And the tone is perfect. I am a also an owner of a Sovtek Big Muff, and although the Big Muff can generate some interesting tones it is definitely a pain in the ass. The pots are tuned horribly, and pedal sucks tone out of your signal when off.
I plan to keep a sharp eye on what Way Huge is doing, they have a great line of products already, and have some very interesting future models coming.