Product review (5 stars): As this is one of the best ways to burn down your house
I ordered this item after reading all of the positive reviews and seeing how much lint others have been able to remove from their vents.  As this is one of the best ways to burn down your house, I figured that I would give this preventative device a try.  The most difficult part of the process was actually moving the washer and dryer out of my way in our somewhat cramped laundry room.

Once that was taken care of, you attach one of the rods to your powered drill and begin sending it up the vent, while adding another rod as the previous one disappears.  You can take the suggestion of taping the attachment points to prevent unwinding (do not use drill in reverse), but I didn't need to.  After a few times sending it up and bringing it back down, I had enough lint to stuff a small couch pillow.  This was from a vent that is only about 12' high (single story to attic near roof's edge) and that had not been properly cleaned out for at least the 5 years we lived here (I know, but I used to use a leaf blower to blow air up the vent).

Our dryer is a bit on the old side and we tend to fill it a bit much, so I cannot say how much of an improvement it made, but I feel better having the vent cleaned out.  BTW, there are other pieces that are included that can be used for this and other tasks, but I have not used them.