Sub-par workmanship if walls are already up. Missed a lot of areas — some cavities are completely empty and I have to basically drill into it to find out. Make sure you drill and check. I will give them credit for coming back a second time to blow additional insulation. This is not meant to say that they are terrible. The product is really good and if you are going with them to fill existing wall cavities, I recommend that you make sure the owner is there to do a thorough quality inspection at the end. They are perfectly fine if you are building a brand new house and you can see the insulation before you close up the walls.