I have a pair of these and I do like them, but for disc golf I tend to prefer my Merrell Moab Ventilators. I never had any leg pain or needed any "break in period" to spread or stretch my feet when I started wearing my Five Fingers, but after a couple of rounds on the disc golf course the soles of my feet get a little tired of dealing with the thin soles on the shoes. And it makes your run-up a little more complicated when you're driving on an uneven natural surface. Again it's not painful or particularly dangerous, but the extra sensory feedback coming through my feet during the run up adds to the complexity of the already challenging activity that my brain is trying to manage.
Also on concrete pads you have to watch the top sides of your toes. If you drag your toes on a concrete pad you're going to rip open the mesh on top of your toes and probably cut up your feet. For more protection you might try the KSO Trek version that has the kangaroo leather upper.
Finally, the KSO stands for "keeps stuff out," which is true for pebbles and leaves and such, but the mesh upper doesn't keep the dust out. Unless you wear toe socks, prepare to have dirty feet when you take them off.