I used one of these at a trainer's and thought it was pretty cool. I asked my husband for the Klimb/Propel package for my birthday. I've had it for about a week, and it's everything I hoped for. My 7-month-old GSD loves it and climbs on it all the time unprompted. We're working on duration/distraction as I want this to be a place I can ask him to go when I need him out of the way for a few minutes, especially when he's play attacking our older dog.
Also, bringing it outside for training. I love that it's easy to clean and easy to carry. I've brought it to the park with us a few times and did some training with it.