Im on the concrete at the plant 10/12 hrs. a day, Ive had my best luck of late with "Timberline Pro Series steel toes" for best out of the box comfort through break in and continued wear..current pair is going on 18 months an they are now starting to break down inside and will be replaced in a few months.
Ive always felt if you can get a good yr. out of a pair of work boots on concrete they are pretty darn good!..I usually walk the insides out before the outsides fail.
Tim