Ordered this bed to use in our guest room. We wanted something that was compact but practical. 
5122….The assembly of the bed was fairly easy for my husband and myself, once we got passed the one issue we had. 
At first he thought the insert where the screw goes into on the headboard was cross threaded until he realized that the metal part that the screw goes through to attach the headboard was crookedbent which made the screw stick out and not be flat against the metal like the other ones (see pics). Once the whole thing was put together it looked nice and firm. 
We’re waiting to receive our mattresses to test out the bed and trundle. 
Will update and possibly give a better rating if the issue is addressed. I know that the one minor issue will not hinder the function of the bed but when I purchase something at this price, I expect no issues.