I love that they are stackable to save on storage space.  They do seem sturdy enough to hold a grown man.  The problem I have with them is the seat is very uncomfortable - even with an outdoor chair cushion, you find yourself needing to get up every so often as it becomes "numbing".   Maybe the designer should have rounded out the seat in an ergonomic way.  They seem like they will be durable.  For the money, it's a little disappointing that they aren't more comfortable.