Speaking from experience....wood floors are not as bad as one would think.
We have wood floors, and the barn is going on 6 yrs and I have only had to replace 3 floor boards thus far, and that was from a very aggressive stall walker, and he would also paw in one spot (by feed tub)....the rest are holding up fine.
Our barn DOES NOT smell of urine. However, we re bed daily, and scrape the floor of wet spots daily, and apply lime/stall dry to urine soaked areas. All our boarders and visitors are amazed at how our barn does not smell like most barns.
We did not put our boards straight on top of the concrete however, they are over top the ground which has a layer of quarter down to help w any drainage, and on-top 2x6 spaced along floor as a brace. They are attached to the back and front of the stall using screws.....these screws if came dislodged (which has yet to happen) would not be in the horses way, as they are located directly under the stall front, and back wall....you can still get at them to remove if needed, but are not in the horses way.
Now like I say we clean our stalls thoroughly daily, and we also use wood shavings, not straw, I would guess that if the stalls are not properly cleaned, bedded, and if using straw, then wood floors may not be the best idea, but they can be used w little problems.
Horses are like chips...you can never just have one