This ramp is worth the investment. The rounded edges of the 'stairs' on this ramp have made a world of difference for us. They are so much easier for my pup to maneuver than traditional stairs. She loves and uses this ramp so much I bought the 17.5" for her to access the sofa and the 21" for access to the bed. I haven't had any issues with the ramp moving - even when she's having a good day and goes flying up and down them. This is harder to explain but if you have a pup with bad knees like mine you'll understand: when she's having a bad day, she'll lose her balance going up stairs because her knee gives out unexpectedly. The way the 'stairs' are crafted, there's not much of gap between them and she'll just end up seated in the crevice of the step whereas with traditional stairs, she'd inevitably roll down them.