I took this shoe out today for ten hard miles over HURT trails here in Hawaii. It was muddy, slippery, heavy ups and downs, plenty of roots and rocks, rainy, slick, you name it we packed it all into 10 miles.  Right from the start this shoe impressed me.  It grips slick surfaces well.  Even if it slides along a root I felt it trying to grip and resisting an outright slip, giving me those precious splits of a second to adjust.  These shoes are great mudders. They did well over all the terrain and obstacles I ran into. Good cushioning and support for my needs. I buy all my shoes large, but the 14 fit as well as my various Adidas which I have been using.

One complaint with the shoe is the thin insole.  I pulled it out and put in my own.  You will have to make the decision based on your needs and the feel.  The shoe itself has good cushioning characteristics and it took hard uneven ground well.  I ran hard and I did not develop any tendon related knee problems. the built in gaiter is nice and seems to work well. The only problem I found is that if you get water into the shoe it is hard to purge as there is an extra fabric layer blocking water outflow. It is a concern for those long runs in very wet weather when you need to have the feet drying as quickly as possible. The lacing system, which has an automatic lock, is OK.  I don't particularly like thin laces but these seemed to work well.

I can not say if this is an ultra shoe just yet. I will post a comment after a 40 miler. But I have experienced nothing to say I can not do 100 miles in it.

Update: I've run twice through the muddy hills for about 40 miles total. I have been happy with the shoes performance. However: I noticed that the green front toe protector, that comes up off the sole, is breaking loose of the toe on both shoes.  This is a problem I have had with previous Sauconys. I intend to shoe goo it. But it is a disappointment that the shoe does not hold up as well as I had hoped it would. I've dropped the rating by a star as a result.(later upped it.)

3/2015  This pair of shoes turned out to be one of the best wearing shoes I've owned in a long while.  It proved very durable after I did a little shoe goo  repair to the toes.  I morn the fact that Saucony dropped this style.  I'd buy a couple more pairs if I could.