Product review (5 stars): Good quality product, works great, highly recommend!
I just got this in the mail yesterday and used it last night.  It worked great, and I loved it!  I was really impressed with how good it worked and how easy it was to use.  My dryer vent is flexible vinyl hose and probably runs 12 feet or so with two right angle bends.  One of my concerns was that the using the brush with a cordless drill may be too aggressive for the vinyl, but the brush was actually a good balance of being soft and flexible enough for the soft vinyl and to make it around the right angle bends, but stiff enough to do a good job cleaning.  The extension poles were also a good combination of being flexible but also stiff enough to push through the vent and also bend around corners.  The turning motion of my drill also helped to feed the brush through the vent line.  The vacuum/dryer vent attachment adapter was helpful too.  This kit comes with detailed instructions and a handful of accessories to help with cleaning.  I have had this on my wish list for quite a while and I'm  glad I finally bought it, I highly recommend it!