I hate working on Dysons! You can't take the cyclone apart, and that's all I clean when I get one in for refurbishment! I don't even WANT to know what it takes to get into a ball model! 
That being said, Fantoms are far easier to completely break-down for service. Convertibles, too,but I rarely encounter a Convertible that needs anything besides a good cleaning! I wonder why! 
