Five Fingers KSO design depends on many factors and your personal taste
Based on previous models, Vibram has chosen to use a polyurethane template of 3 mm thick, under the ball of the foot. The more structured design Bikila gives a sense of support under the arch. I did not find this at all unpleasant, but it was remarkable.
Feel barefoot
Used for Sprint, Classic, and kso is a reduction in sensitivity or sensation of barefoot Bikila. The sole is thicker and pods of grip on the sole to add extra thickness and reduce direct contact with the ground. The Five Fingers KSO is very flexible, but less than Sprint models, Classic, and kso. Those who are not accustomed to the lineup FiveFingers Bikila is probably the very flexible, while comparing to previous models is a slight reduction in the soil feels. For a specific execution model, the added thickness allows an area of little more flexibility for some users, while others may find the decreased sensitivity of a strike against the shoe. When you depend on many factors and are your personal taste.
The Bikila breathes well. Sweat is bad, but away from the padding and moves well through the thin material covering the forefoot. Shoes are comfortable to wear during the performance and provide an environment to run infinitely more comfortable compared to a traditional broker / coach.
As with all models the Bikila FiveFingers is not waterproof. The extra thickness of the plant provides greater protection when running on wet pavement as compared to the Classic, Sprint and kso. However, standing water is a way for prolonged use in wet weather.
As with all models Vibram FiveFingers, is attention to quality of workmanship and quality materials to make a very well done. New fabrics have been used in this design and as usual, Five Fingers Shoes has chosen very carefully in order to take full advantage of these special shoes. The sole is a new design and materials used on top of all appear to be new.
The Bikila appear to be the size of my feet. I wear size 44 and trekking in KSOS Bikila feel like a very good fit in this size. Wait for a better adjustment due to the design of the shoe. Due to the snug fit some may find the need to go up a size, but I suspect this will be rare.