Good to see an explanation on the durometer of the new EXO 3C tires. I was wondering why my set felt so much harder than the DH version. I figured they just labelled the tire wrong. Now I know.
I've been running the EXO tires on my "AM" bike (Knolly Delirium T) for about 3 months now. I went from the DH version to the EXO tires and dropped 1.8 pounds off the bike. It made the bike way easier to pedal and it is much easier to convince myself to do multiple pedals laps now. The thing I like about the tires is that they feel similar to their bigger cousins on dirt and in mud. They have similar cornering characteristics to the DH tire, but I find they roll over a bit in really hard corners (as to be expected from a thinner sidewall). One other thing to note is they do not hook up nearly as well on cold wet roots and slick rocks as the full on DH tire(this might get better once things warm up).
One other thing to note; I'm running the tires tubeless (with no problems) so that might contribute to the thinner sidewall feel.
Overall, these have been great tires and I've still been able to tackle all the lines that I would normally do with the bigger tires. I'm not sure I would run them on my DH bike, as the bike is a lot faster and who doesn't like monster trucking through a rock garden!