These shelves are great once assembled. Assembly can be pretty tough for one person. Since I purchased two of the units, I was able to improve the process on the second unit. I stacked the shelves, with holes aligned on the floor first and then put the posts in place. I then assembled the top shelf in place first. This, more or less helped hold the unit together for the rest of the assembly. I then raised up the second shelf from the top and assembled it. Each shelf assembly makes the structure more stable for assembly of the remaining shelves. I recommend updating the instructions to provide this assembly order.
I purchased 4 of these sight-unseen based on good reviews and specs. When I was first putting it together I thought it was pretty nice. The leg poles are very sturdy and the shelves are good. What is NOT good is the way the shelves attach to the legs. These shelves are supposed to hold up to 250lbs each, but I found that the shelves were not that secure and they would easily start to slide down if you pushed on them or dropped something heavy on it near a corner. It might be ok for very light duty, but there are much better shelves out there with much better shelf attachment mechanisms than these. I returned them all.
It's not perfectly balanced, but no DIY shelf ever will be. But it's strong, adjustable, looks good, and functions. Very gruntled with this purchase.