Product review (5 stars): Get it. Use it properly and it will pay for itself.
I ordered from Amazon and cancelled due to cold feet reading some 1 star reviews about stuck brushes in the flue.  One idea was to use clear vynil hose onthe shop vac and work it from the inside up and vacuum it clean.  I live in townhouise and stack in in middle and is nearly 30' but thank the lord straight.  I clean dryer 2x year with complete disassemble so I didn't thin the stack could be that bad after 3 years in a new house.  Poked my nose up the pipe and it looked dirty but not clogged.  Certainly on it's way to becoming a problem.
Went to Lowes' and saw the Lint Eater for similar price. i opened it and saw that it had the metal thread brush insert and the locking hex screw.  The fiberglass rod tips were secure and the rods are light and very flexible.  I bought it and figured it was the same price and i could return if not pleased.  Removed dryer and assembled AS PER INSTRUCTIONS with duct tape around the rod ends just in case.  Without the drill I shoved it up the pipe (all 12') and turned it by hand(I didn't follow the instructions).  3 handfuls of lint came out.  Looked up the pipe and saw a nice clump of lint blocking the pipe now because i pushed it up there.  USE THE DRILL and use it CLOCKWISE.  The brush is screw shaped and pushed the lint down when turning. The brush on a 4" flue pipe is lose enough not to bind.  If you have a 3" I suggest using the smaller supplied brush ot triming down the auger brush.  Luckily, they include a vacuum adapter and that sucked the lint stopper down with my shop vac. Pipe is nice and clean all the way up.  The lint didn't get a chance to get any higher buildup so I didn't go back and buy the extensions.  I plan on using every year and hopefully won't be so high up either.  Ran dryer on air only for 5 Mounties.  Pipe is clean like new.
Good product but make sure it has the new improvements on the brush.  Waste the $1 on taping the rods too as a piece of mind.  Bends seem like no problem.  Don't spin drill too fast around bend.