A belt sander is very good at taking off material. There are more than
one factor involved. How hard is your floor material? What number of the
sanding belt is used? The accessibility of the work area (some belt
sander has shape that allows it to get close only on one side) In
general, I'd venture to say unless your floor hight difference is more
than 1/16" or you better have very steady hands. After the belt sander
it will take many pass of finishing sander to get rid off all the marks
left by the belt sander.

FC