These are very easy to put together and are very durable. They are easily stackable. I have found that taping the "hand holds" open keeps the box intact when moving them around several times.
I use these boxes for storing bulky files. I'm in the trucking business and files get bulky with bill of ladings delivery receipts etc. Also use them for monthly expense files. I have boxes stacked six high with no crumbling. each box must weigh about 20 poundds or more.
I use these both personally and for business. I store the prior year's accounting records in these boxes as well as outdated personal records that I'm not ready to completely dispose of. I have also used them as "moving containers" for small and medium-sized items. They are easy to assemble and the lid fits well.