I've been using the stepper for a few weeks, about 30 min. each time, and I love it! I go at the fastest pace I can, safely, on the unit. I usually work out on an elliptical at my gym, but lately I haven't had time to go to the gym, so I bought the stepper. The unit doesn't take up much space at all, is light enough to pick up and move around. I have a spot for it in our mud room, set it up across from a counter where I watch shows on Fire Tablet while I work out. I pair it with a resistance strap.
I did have to contact the seller after one week b/c the interface would indicate I had stopped even though I hadn't, and the seller immediately responded to me, sent me a new interface (which is easily replaceable, it just pops in and out). As it turns out, the problem was a simple fix: after using the stepper for a few minutes, the interface wiggles out of it's holder just a bit, so the system thinks you've stopped. I'll fix the issue by using black duct tape to firmly secure the interface in its holder.
Stepper was usable right out of the box. I love this thing b/c I can get a quick workout at home!!