I have the 18 hp Billy Goat and I've had to take off the tube for a clog ONCE this whole year. We've even sucked up non-leaf debris - potted plants, knockout rose cuttings, perennial debris...
We rake-feed the tube. It's new clear tube with little ridges like someone said. Sticks are a pain, but most of the time not an issue. When one gets stuck across the intake, I turn the rake sideways and crack the stick real fast, up it goes.