Pretty sturdy as far as being a shelf. We had to purchase better drywall hangers as those that came with the shelf were horrible (I'm pretty sure at least two or three are still inside the wall but they fell inside and are forever inside the wall). 

The shelves go together easily enough but then leave silver screwheads showing. The kit comes with 'black' plastic caps to cover those screws but those caps pop off and have zero staying power. We are planning on gluing the caps on.

Honestly, they are very strong and sturdy shelves and the they are smooth with straight edges and a good paint job on the exterior and easy to put together. But, having to buy the attachment to  the wall wasn't expected or necessary since they sent hardware (just cheap hardware that failed - the mfg should upgrade) and then the black aesthetic plastic caps don't work. Again - the mfg should have  better design or fitting for that. But we'll glue them on and hopefully that will work.