I picked up a pair of VFF KSO's last fall for running, but have not worn them hiking. Prior to "retraining" myself to run in minimalist footwear, I was not able to run due to severe knee pain. I also had major knee problems backpacking. One year ago, I backpacked about 16 miles in two days and that was about as far as I could go as my knees started to hurt too bad.
Within minutes of starting to run in the KSO's last fall, my knee pain was gone and to this day has remained mostly at bay. I can still feel twinges of pain here and there, but it is nothing like what I experienced prior to using minimalist shoes.
As discussed previously, it is necessary to completely retrain yourself to run and walk in minimalist footwear and this takes time and patience!!
I am currently up to about 25 miles per week running and up to a 10 mile run as my longest run. I am planning on doing a 12 mile trail run on Saturday in the KSO's now that the snow has melted here in MN.
In December I day-hiked 12 miles of the AT in Georgia in my Inov8 295's with no knee pain and this included some running.
This last weekend, I backpacked about 22 miles in two days on the Superior Hiking Trail with no knee pain and a 25 lb pack. I hiked it in my Inov8 295's as much of the hike was either in snow, on ice, in icy slushy water or muddy conditions. The KSO's are definitely not the right footwear for that application.
Any way you look at it, I feel that training in minimalist footwear has cured my knee pain that I was previously experiencing in traditional shoes. It has also made my feet and legs much stronger and greatly increased my sense of balance as well as core strength. I'm not quite ready to say that the VFF's are the right shoe for hiking/backpacking as I've not tested that, but I am planning on trying this year.
I have more information about my transition to minimalist footwear on my blog if anyone is interested.