I agree on the bigger decks. My CC zero turn has a 60 inch deck on it and it mows great in the wide open spaces.
But, I also have a wind break planted and buildings to mow around. The 60 inch deck is too big for these areas. I know some guys/gals have gates to go through and the 60 inchers prolly wouldn't fit. So each sized deck has its place.
On a side note, I've seen some of the older 38 inch cast iron end decks on 70's and 100's do one heck of a nice job mowing, too. All depends on the setup of the deck and sharpness of the blades.
