I was wondering if this was going to fall to a "Mine's better" arguement.
Liflod's right on the mark; you may love one and hate the other, or love them both. I'd have said a T20 machine would out perform the differential style trans of the Argo once too, until I started riding with Argo guys. They're impressive machines, to put it mildly. They handle differently, so if you can get a little experience in each machine you'll be able to make a good choice. Good Luck.
Stuck in the seventies- not in the swamp.
(6) Attex, a Hustler, a Super Swamp Fox, (2) Tricarts, (3) Tri-sports, a Sno-co trike, 3 Dunecycles, and a Starcraft! ...so far