I was actually surprised at how sturdy these shelves are.  I didn't know quite what to expect, but was pleasantly surprised.  It's def easier to put together with 2 people...  and I would suggest that you have some extra wood glue available...  we ran out of the small tube provided.
We made sure to inspect all the pieces, since other reviews mentioned scratches, but all looked good for us.
Overall, it is a great product, and looks so cute in my son's nursery!