I'm one of those who think Slaughter of the Soul is an amazing album. I remember, like 12 years ago, when we started listening to it (a friend brought a cd from Europe in 96). It was groundbreaking.
The best Metal Magazine in Brazil published a detailed coverage of 2008's Wacken.
They report that, during At the Gates' gig, there were several members of other bands checking it onstage, and celebrating as they played songs off Slaughter of the Soul. The most celebrated song was "Blinded by Fear".