Depends on conditions and dealer for me. On ZTRs scags are faster hands down and can handle a wider variety of conditions. In a perfect weed free dry lawn Exmark will leave the best cut period. If I were you I would go with scag. I have been running Exmark for years but will be getting scags or ferris mowers to replace them.
I've never been skydiving, but I have zoomed-in on Google Earth really fast.