Product review (5 stars): 1) The Shop vac attachments which come with the kit (they allow you to blow air out the system or suck the material back to you
We had a Kenmore dryer for years and it was taking a ratio of about 3x for clothes to dry, after we washed them. I bought the green As Seen on TV kit, which only lets you get about 2 feet into your dryer or vents. We installed a new LG dryer this morning, which immediately on the first load showed an error (90% blockage in the line). I bought the LE kit and the dryer is working again.
We're going to have a professional clean out everything anyway, our vent line has a 90 degree angle up from the ground floor, out on the roof on the 2nd floor. Ridiculous... But this is a 13-year old house and we picked it up 3 years ago and we haven't had anything done to the vent system, so we have to assume no one did anything.

I have some caveats which do not detract from the overall experience...
1) The Shop vac attachments which come with the kit (they allow you to blow air out the system or suck the material back to you which you auger out) are dimensioned for, and state they should only be used with, a 2" hose. I have a 1" hose I think, but a little duct tape fixed that problem real quick. Smaller hose worked fine. I only worked from the inside out (from the dryer as far into the vent as I could reach).
2) You have to learn the rhythm of the fiberglass poles. Basically you are whipping the auger through your line (I pushed in all the way in, up to 12'; the clockwise motion of the auger moves it gradually out of the vents). My drill won't allow me to adjust the torque or RPMs, so the first couple times you try it you end up un-screwing the poles, no matter how much you duct tape them. And any real resistance will kink up the fiberglass poles. But if you keep to the mid-range RPMs, it works really well.
Anyway, these clogged vents start 15,000 fires... http://www.abcactionnews.com/money/angies-list/thousands-of-fires-are-sparked-each-year-by-clogged-dryer-vents
Again, we are going to have a deep clean on our system. But this will be our maintenance system between the professionals.