Difference between square and round decks?

[FrankenScagMachines]

Is there any difference in squared decks or rounded decks on mowers? You know, like curved edges or straight ones. Do they cut or discharge differently ? Do they tend to clump or does grass stick to them differently? Different airflows? I'm thinking about making a squared one for an old garden tractor because the one it has is too small and i'm not gonna use it to mow much, but just large areas (doesn't turn too tight) and I want something to do. (like I don't already have enough!)
Thanks,
Eric