All though I have access to some of the latest and greatest mountain bikes I still have the most fun going fully rigid. A couple of things i've discovered is the larger the diameter up front smoothens the ride and provides better roll over. Out back maximum volume with lowest pressure possible for some cushion and traction. The Instigator is built to handle a 130mm travel suspension fork so the rigid 29er fork and wheel play nice with the geometry. Super fun bike.
Surly Instigator 69er/96er by SaddleUpBike, on Flickr
Surly Instigator 69er/96er by SaddleUpBike, on Flickr
Surly Instigator 69er/96er by SaddleUpBike, on Flickr
Surly Instigator 69er/96er by SaddleUpBike, on Flickr