Initially, my miniature Dachshund was afraid to use, had trouble w/first stair, as it is a taller step than the others. She also is alittle arthritic in her hips, but she is doing better.  Coming down the stairs is not a problem.  My new minature Dachshund puppy is fearless and manages fine.  Was easy to unfold, nice for travel.  Reaches my high bed w/california mattress and pillow top (about 29 inches from ground).  Tried many others, and so far this has been their favorite.  I also have a Corgi, and while he is not crazy about doing stairs and would rather be lifted, it is plenty strong enough for him.  

Pros: steardy, lightweight, easy for travel or fold out of the way
Cons: steps could be wider and deeper.