In reply to Leo Roberts:
Another vote for Altra! Even though I myself just bought my first pair (King MT) now, they are very light and have super wide and comfy toe box. Now, it depends what running shoes you are used to - I have been running mostly trails in Vivobarefoot for couple of years now so for me Zero drop (Altra do only zero drop shoes) and wide front part of the shoe is essential. To be honest, I would not look for another shoe if I don't need more aggressive grip for muddy downhill terrains. From reviews I read and discussions I had with some ultrarunners it seems that Lone Peak is their nr one shoe. I went for King MT due to some personal preferences. To summarise - if you are looking for a lightweight trail running shoe, Altra is definitely perfect option, just be careful with the zero drop - if you are used to high drop, jumping straight to zero drop might not be the healthiest option (Inov8 have many various options and very good reviews, but no personal experience). If you are used to zero drop, go for Altra. (And if you are used to zero drop, running rather long distances then sprinting, preferring more trails then pavements and not looking for super aggressive grip, think about trying Vivobarefoot, but then be patient with the transition barefoot shoes usually need )