Product review (5 stars): Works exactly as you hope it will
Long story, but, hoping to give details that might apply to other homeowners and solve several issues.  Skip the next paragraph for review of LintEater only.

Over the years, I had grown very frustrated with the design of the dryer vent in our home - from the dryer, the vent goes down an internal wall, underneath the foundation, back up an outside wall, then, out.  (a total of four 90-degree turns) The regular washer and electric dryer that we had before would create lots of condensation in the vent line, and would require vacuuming out with a shop vac about every 6 months. I would routinely extract about 3 gallons of water each time.  In April 2013, I switched to an HE washer and a gas dryer.  Also, switched from a flex vent hose (from dryer to wall) to a semi-rigid hose that added yet another turn to the venting, but, was still within the recommended limits of the new gas dryer.  The HE washer solved the moisture problem, but, the gas dryer was taking even longer to dry than the electric dryer.  A check of the dryer indicated that the gas would only burn for 7 seconds before shutting off.  I was told by an expert that I had a ventilation problem.  A check of local vendors indicated prices ranging from $120 to $159 for dryer vent cleaning.  I searched and found the Gardus LintEater online and decided that the price point was right for me to try this myself.  Glad that I did.

The Gardus LintEater worked exactly as expected and did the job.  It took about 2 hours to completely clean the vent.  It was a little tricky to get it to push through the 90-degree turns, but, once it did, it moved forward.  It ended up being a 2-person job - one to hold and power the drill, and one to grab the turning rods with bare hands (no burns!) and push the rods through.  I had the shop vac hooked up on the indoor side of the vent and pushed the cleaning brush through from the outdoor side.  At about the 8 foot mark (4 feet from the indoor side), I encountered a tightly packed mass of lint and the brush had trouble breaking it up.  So, I switched to cleaning from the indoor side.  The vac hose adapter has a small hole at the top that allows you to vac and clean from the same side simultaneously.  That did the trick - when I encountered the mass from the indoor side, the brush was able to break it up along with the help of the vac suction.  In a matter of seconds, the LintEater had cleaned out about a 1-cubic foot mass of lint.  The 12-feet of rods that come with the kit was perfect for cleaning the entire length.  After reconnecting the gas dryer, it was absolutely amazing at the difference in the airflow.  The dryer works super fast now and I cannot be more pleased.  This is one of the best investments a homeowner can make!

Note: I did have to make the adapter in order to attach the rods to my corded drill - just a matter of cutting the head off a bolt.  I have a 3/8" chuck and the rods require a 1/2" or larger chuck.  If you have to do this, you will know what I mean - just read the instruction manual.  It was not a problem to do, but, I did happen to have the right size bolt already.  Last note: the rods are fairly durable - several times in the process (going around the 90-degree turns and when hitting the lint mass), the drill would turn the rods faster than what they could physically turn, so, the rods would twist up into what looks like a long pretzel.  I fully expected them to break at that point, but, they did not.  I was very happy to see how the rods could take quite a bit of twisting without breaking.  Now that I will be doing routine cleaning, I don't expect to have this problem.

Bottom line - if you even think your dryer vent needs cleaning, buy this system and use it; you will be happy you did.  This advice is coming from someone who hardly ever writes a review.  Happy cleaning.