Read some of the negative reviews... retards welding in lace up hiking style work boots that complain about the laces and nylon parts of the boots melting.
I've found the majority of Amazon negative reviews (no matter the product) are full of idiots complaining that the world isn't idiot proof.
The Keen Detroit steel toe hikers are great for casual work use (like an office guy wandering through the shop getting in the way...).
I usually get two years out of Keen Detroits wearing them primarily on oilfield locations doing inspections.
If you do actual manual labor for 8-10 hours a day in a job that requires "real" work boots Keen aren't going to last very long.
But for what it sounds like you'll be doing they'll be fine.