I bought some of these during the sale a few months ago. I put the Bow Hush on one bow and the hush puppies on another. It is more time consuming to attach than many other silencing systems, but not unbearable. I've found both items to be quite durable and they stay in place.
I was concerned the Pups would slow down my rig (compared to a pair of whiskers (divided into 4ths) because they "looked slow". I put them through the Chronograph. Nope, I'm happy to say there was no difference in FPS between the two.
I have to admit though the bow I'm trying to make quiet still isn't as quiet as my all wood riser bows, even with this treatment, but I'm still hunting with it.