Comments about SMI Oak Stackable Files:

I ordered two of the 3-Drawer flat files with tops and set them side by side and placed my sofa-bed on top. I was very concerned that the flat files might not be able to support the weight of the couch and people on it but they are extremely sturdy and even supporting the weight of multiple people I have had no problems.
It's important to note that the couch does sit very high. I am quite tall and my couch is rather low- on top of the flat files it's awkwardly high even for me. My solution works for me but may be a better indicator of the flat files' durability rather than a practical solution for others. Additionally my couch sits flat against the floor rather than on feet so the weight is distributed evenly.

The drawers glide beautifully and the exterior is attractive though slightly lighter on my drawers than pictured here.

They were admittedly quite expensive but these flat files are worth every penny.

Comments about SMI Oak Stackable Files:

The quality of these cabinets and the book shelf is very good: drawers solid and slide well, seem stable. Bookshelf seems a bit odd given that it is the same depth as the files, so deep enough for two books, but is OPEN on top. My gripe is that the picture described "files and bookshelf" and did not mention that it also included a cap (I assumed the bookshelf was finished on the top). So now I have to re-order to get the cap to finish the unit.