I have a 8 ft dual spindle Kodiak and am very pleased with it. When I first got it I had problems with it leaving a strip in the middle. I sharped the blades and dropped the rear of the cutter. No problems since. This cutter seems to cut better in an almost level position, front end only half an inch lower than the rear. At first mine came from the dealer with the tail wheels all the way down, back of cutter all the way up. It cut horrible.
Try adjusting it so it's almost level and see what happens.