Shed construction is flimsy.  

If its not laid out square, you will pay the price later.  We were unable to drill into an old concrete base to anchor the shed so we laid 2x4's on top of the base.  In spite of repeated measuring, we were unable to keep everything square.   

As a result, we have a mismatch on one corner and our doors cannot both close and there is no point in installing the latch.  

The supporting angled beams at the corners are awkward to drill the screws into. Otherwise I would undo everything and try again.

The inside of the shed lacks useable supports for installing shelves or pegs.
I worry about the shed blowing down or away.   I have already had it shift about 4 inches even though there is a weight on the roof.