Daniel .... you hiring the GPX units? They're not the easiest to get your head around if just starting, if they're yours i'd be getting in a bit of practise. There are no x marks the spot locations, any area that the old timers were prospecting in will give you a chance to pick up something, as a "general' rule the ground will be shallower" on the sides of hills/gullies, the bottom areas usually have more material washed down (silt/leaf litter build-up) so generally the gold will be a bit deeper .... still the 5000 should do the job for you.
Don't rush or just jump from spot to spot, go slow, cover a predetermined area throughly before moving on and just because others have dug targets there doesn't always mean they've found all the gold.
Good Luck, T.