Aquaseal. Seriously.
No matter which brand of shoes you choose, they're going to get eaten up from rotation, toe dragging, etc., on concrete tee pads. A tube of Aquaseal - urethane repair adhesive and sealant - costs ~$7.00. You can double, maybe triple the life of your shoes by globbing on some Aquaseal on the high-wear spots. There are other brands of similar materials on the market; I prefer Aquaseal because it remains pliable forever. Other brands I've tried become brittle and will crack or peel off after a couple of months.
Get a tube and fix the Keens you already have. Seven bucks. BAM!