I know Toro owns Exmark and the Z334 is a rebadged Phazer. Heres what I've already gathered from the archives, brochures and websites: 1. Toro has the Kawasaki KAI FH580V, Phazer has the non KAI. 2. Deck is a little different, Phazer has four chains holding the deck while Toro has 2 chains. 3. Toro has a different height adjustment. but what else has been improved since the original Phazer?