I was expecting the shelves to have a bit more substance than they do, their strength relies upon the frame but will likely be prone to warping as they are quite thin and bendy.

Erecting the shelves is almost totally reliant on having a rubber mallet to ensure the tabs go through the slots properly.  The instructions are minimal and you do need to ensure that the tabs are slotting down on the structure - I managed to turn it upside and have some going the wrong way (risking the shelf brackets slipping out, disaster!) and had to redo those shelves.  Once completed however it is sturdy and takes a fair amount of weight, but the shelving does look very cheap.