I purchased the Vertical Plate Tree recently. I have been using it for a few weeks now. I am impressed with how sturdy the unit is. It's really over built, which is appreciated. The wheels are very solid as well. I have my equipment in a garage with a standard slope. Even with the slope, the weight tree does not roll down the garage with the wheels unlocked. When the wheels are locked, it is impossible to move- yes the wheel locks work. I have mine loaded up with about 500 lbs of plates. The only negative I have is that 2 bolts on the triangle bracket on the bottom will mark up the plates if you push the weights flush up against it. Great piece of equipment!