Product review (5 stars): Worked like a champ!
I was a bit leary about this product before purchasing.  I was affraid the brush head was going to break off in the vent piping somewhere I couldn't reach it and I would end up having to rip apart a wall/ceiling to access it.  I carefully read the product instructions and found the unit to be plenty sturdy for the task.  The plastic rods have metal male/female bolt ends so no worry about those stripping or breaking.  Setting up for the task (moving the dryer, pulling out the shop-vac, reading the instruction manual, etc...) took 3 times as long as actually cleaning the vent.  Very fast process.  If you read the instruction manual, you'll be fine.