Works pretty good, my cats don't like it very much though. Usually get about 5 to 6 minutes in before they start freaking out.
$70?
Cheaper to just get another dog?
Mine didn't cost as much, got a small one. I think mine was 25.
Yea smaller ones are a bit cheaper ($25-$50 range). You can also get one that has a universal connection to a vacuum cleaner hose.
They are very heavy duty brushes. If yours is light in weight (for a brush), probably not the real thing.
But yea....pretty much amazing.