There are almost as many chippers as there are applications. If you specialize in tree work and need the best, I would choose between Morbark and Vermeer self-feeding. I could fill 2 pages with good and bad of drum vs. disc. At Davey Tree, we used Brush Bandit and Vermeer 12" disc. The Brush Bandits suck, they vibrated apart and we were welding patches on them within 6 months of purchase. I have always liked the Morbark drum, self-feeding, but limited access here. No dealers nearby, and a good dealer is more important than the brand. Vermeers are tough, but harder on the ground crew with the higher, longer feed table. My crew at Davey loved the Bandits if they were running that day, but the Vermeers always ran. As foreman I took the Vermeer so I would get done on time without breakdowns.