Product review (5 stars): This is the one to buy!
Excellent.  Easy to use, amazed at how much lint that dryer vent pipe was clinging to!  We have a REALLY long vent path so I used all 12 feet from each direction (outside towards dryer; dryer towards outside).  Worked like a charm.  Best of all, the dryer is working much faster now so we'll save the money we spent on the product off our electric bill.  Yay!