Another, lesser, reason to consider is that the belt drive will be more susceptible to damage/clogging by chips thrown up from the cutter... unless you add a shield which therefore increases the static weight of the gantry.
How do Irving.

Weight won't be a problem weight till you see what I'm using for the Y axis.

t'll work, the only issue is that you lose z-clearance
Now you've lost me,Irving? I can only think you mean when the gantry is at homing on the Z back?