Shoe review - Karhu Fast Fulcrum

I bought these shoes for a steal and have tried them out enough times to review them. The concept behind the fulcrum design is to encourage mid-foot strike instead of heel strike.
FUNCTION: I find that the shoe actually does what it says it does - that is, I feel myself leaning into my stride as I run. If you don't lean, you sort of land on a lump in the sole (which is the "fulcrum"). I'm liking this so far, but I'm only wearing these for short, speedier runs. That's good, because the shoe is designed for speedwork and has a very minimal outsole that you could probably wear right through in one marathon. Karhu does makes other shoes that are designed for longer runs and have more stability.
FEEL: The shoe itself is comfy. There is no structure at all to the upper, but that works for me because the toe box is rather narrow and long and my toes are wide and short. The loose upper lets me adjust fit to my foot - but I should mention that in order to do so, I have to do some creative lace work; actually tying these shoes and getting them to feel right takes several attempts. These aren't slip on and off shoes - you have to rework the laces every time for correct fit. The insole and outsole feel SO cushy to me, and just standing in the shoe is comfortable. But take that with a grain of salt because I'm comparing these to a pair of Nikes with about as much cushion as a cinder block.
You should be aware that the shoe provides little or no stability. The fulcrum sole helps guide your foot strike, but your arches and ankles are on their own. I imagine that I pronate pretty badly in these, although it's too early to tell by the sole wearing. If you need support, or you are a heavier runner, Karhu does make a more supportive shoe.
FIT: Reviews for the shoe warned that it ran very small, but I did not find that it ran especially small for a running shoe. I wear an 8 or 8.5 shoe and bought a 9.5 Nike; I bought these in a 9.5 as well and actually I find them a little larger than my Nikes. This is partly due to a roomy inside since there's no upper structure, but most of that extra room is in the toe length, which is a little long and narrow. The long toe plus a not-very-narrow heel and the fulcrum design can tend to allow your foot to slide forward. This would be a problem if I wore these for distance. By the way I have wide feet and I don't have a problem with the fit, although the shoe appears "European" (narrow).
PRICE: The shoes are pricey for what's basically a racing shoe, $115, but you can find them for less (mine were under $40 including shipping) and actually Sierra Trading Post has them on sale again if you're interested, although for about $50 this time!
OVERALL: I was hoping these shoes would cushion my knees and maybe work with me to increase speed. I don't expect my shoes to actually make me run faster, but I feel comfortable knocking a few seconds off in the Fast Fulcrum (plus, it's called "fast", so you've just GOT to be inspired, right?). It's hard to tell if my knees are doing better or not because I'm wearing other shoes for longer runs. I'm loving them for a soft, fast, short run (3 or 4 miles) and if I ever get a weekend off and can squeeze a race in I'd definitely wear these!