If you have been following some of my exploits in five fingers, you have read my disappointment with the KSO for trail running. I continue to run in them on streets and grass without any issues.
Well, five fingers has created the right amount of protection to still have a minimalist feel to running on rough terrain.
The five finger sport/trek provides enough protection for open field, packed trails, and rocky paths. I broke mine in at my parent's farm in East Texas in their open fields and wooded paths.
I found them light and flexible like the KSOs, but with enough protection not to slow down on rocky paths and hard-packed trails. I had no deep bruises in my insole or heel like I did with the lighter KSOs. The only draw back was the occasional long-stem weed between my toes, but that's part of the five finger experience.
I like the added traction on both the sole and toe of the shoes. The added plastic covering on the top of the toe seems like it will come in handy on wetter surfaces. Like my KSOs, it will take a couple of more outings to have them stretch to my actual foot size and shape. I will take them out on the trails of Arbor Hills here in Plano soon to test them on more rugged terrain, and I plan to run a 30k trail run in them later in the year.
I got my sport/treks online at ZB Sports.com. They were retail, but you get to choose a charity for part of the sale to go to when you buy the shoe. ZB handled my request quickly, and I was running in them within three days of my purchase. I recommend them!
Let me know how you are using your sport/treks. I'll keep you updated on mine.