I am not much of an expert as I run less than most of the other gals on here, but I did buy trail-running shoes last year (Vasque Blur) and love them. The trails I run are very rooty, so I was looking for a bit more stability than a super lightweight road-running shoe. I don't notice them being hot, but I did not get ones with a Gore-tex liner. I must admit that one of my motivations for getting them was keeping my road-running shoes nice and clean, since the trail I run on can get pretty muddy, so my trail shoes don't stay pristine.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow