Like most people, I hated running. I could go on an elliptical or bike all day, but couldn't run a mile without my legs burning like fire and my whole body gasping for air. But after these shoes, I actually enjoy running now - it's fun and addictive, and shockingly easy - running in these is so effortless, it almost feels like cheating. I'm not exaggerating - if you told me a year ago I could run a half marathon, I wouldn't have believed you. But I did it in these shoes and it was easy.
On a technical note, the KSO's offer a perfect mix of ground feel and protection. So yes, you do really feel the ground, but that's a good thing - your body will compensate and you'll run in a "lighter" style. Put simply, your body knows stomping/pounding the pavement will hurt, so it won't let you do it, if that makes sense. Sure it takes getting used to, but it soon becomes automatic like riding a bike. Stick with it and you'll be running further than before, using less energy than before. I've heard it said that you should only run short distances in these, but I had no problems after 13 miles. Flea from RHCP ran a full marathon (26 miles) in KSO's as well, so it can be done.
What else? I've put over 300 miles on them with only slight wear in the sole, they'll definitely last longer than a regular shoe. I've heard some people can take theirs to 1000 miles, and I can believe it. They truly fit like a glove. Other models either seem too narrow or "shallow", but this one fits my foot perfectly. They're super-easy to put on after you break them in (I can put these on just as fast as regular shoes now - the toes just slide in, even the pinky one) They're lightweight and pack easy for travel. The KSO model also works great in the mud, sand, and water. Cleanup is a breeze. I just soak them in the sink with detergent and air dry. I've only had to wash them in a machine once after a mudrun and they held up fine. I've had no problems with smell like other people, I guess I'm lucky.
There are actually quite a few cons, even though I'm giving this five stars. First, it's hard to WALK in these. Running is a breeze, since you'll be doing it on your mid/forefoot. But walking inevitably involves heel-striking, so these aren't the best shoes for that.
I used to get blisters in about 3 different places (heel, big toe, arch) when I first got them and had to constantly protect my feet using band-aids. This problem resolved itself, not sure how. (Either my feet got tougher or the rough edges of the KSO's got worn down)
There WILL be times when you need more protection. Running on harder surfaces like concrete will feel VERY different from running on asphalt (I never even knew there was a difference till I started wondering why I hurt after running in certain areas). The Bikila and Bikila LS have more padding underfoot specifically for city surfaces, but something about running in them feels...off. There's too much arch support, and the increased padding means less ground feel - which results in poorer form by me. Plus they're just not as much fun to run in. Also, running on gravel or stepping on a rock WILL hurt. They do make VFF'S (Trek, Treksport) specifically for trails and rougher areas, but they are obviously thicker and more cumbersome. You can't have it all yet I guess.
Also, make sure you TRY the shoes on before you buy them. There is no definitive sizing chart - I wear a 10.5 shoe in most brands and I wear a size 42 KSO. My friend also wears 10.5 shoes but wears a 41. I know some people with 10.5 who wear 43. You really have to try them on and see how they fit. Even sizing WITHIN VFF's is off. I tried a pair of Bikila's that crushed my toes in 42 so I had to upsize to Bikila 43. I really wish there was more consistency with the sizing.
Finally, you'll never go back to "normal" shoes again. That sounds like a compliment, but I actually do mean that as a con. There's times when I want to wear a regular shoe (either for aesthetic or protection reasons) and I just can't - running in regular shoes now feels sluggish and awkward at best, painful on my knees and lower back at worst. I really do think running in VFF's changes your body to only accept minimalist, zero-drop shoes, so if you don't want to be stuck with those for the rest of your life, think twice about getting them. To everyone else, I can't recommend these highly enough.
