For the life of me I can't find any documentation on eXmark's site that describes what the real differences and reasons for having 2 different lines. The 'Lazer Z' and the 'Lazer Z Advantage Series'. What is the difference between the two. The only difference at all I can tell is in the brochure for the Lazer Z line as a whole describes the Advantage Series as the model that will cut slightly less grass per hour than the plain Lazer Z model. Anyone know what all the differences are and the reason for the 2 lines?