Whats usual for miles and hours?

I plan on buying a used RZR, probably a 20010 or 2011. I see some range from 300 hours to over 1000 hrs and from 200 miles to 2500 miles.
Whats more important? miles or hours?
Is there a usual amount to go by? I see some rzrs with only a few hundred hours and the bearings and ball joints have all been replaced . Is this normal?
Is there any models? years to avoid?
Thanks
Robert
Pittsburgh, PA