I have one
its not the tube style, its a tray but the same idea.
they are built very well
its easy to oversmoke with these things.
I tried it on some bacon. I just lit it and put it in my offset and let it go.
The bacon was terrible, smelled like an old ash tray.
After contacting Todd, the maker, he told me that if the smoke is cold then it hangs around and is easy to oversmoke
He recommended a temp of about 100f, when I did it it was cold out, he even suggested some guys put a 100w light bulb in the smoker just to give it a little heat.
Makes sense since I did notice that the smoke was just barely wafting out of my chimney, kind like the smoke out a factory chimney.
With a little heat I am sure it would circulate faster through the smoker