Inherited tenants are usually a negative, however in that area leaving the duplex totally vacant makes it a target for thieves to come in and steal your pipes, furnace, and hot water tanks.

Use to use water, it does not work as well over the masses.

I have had a home destroyed by fire; never by water.

PRELIM LAND PLANNING- do a preliminary layout, please remember stream buffers, specimen trees, ANY jurisdictional waters (its a good idea to have you county water systems guy come walk your property with you to verify any jurisdictional water systems and what the required state and county buffers are for those systems).

Each unit is individually metered for power and water. 

My extensive real estate experience consists of 1 flip.I have an idea and I'd like to test the waters here in the forums.

Water/sewer is shared and can be sub-metered. 

So if your big into water sports, living in the desert could have all the profit in the world but it's going to be miserable hell and odd's are after some months the profits wont matter.

Looking at pure spreadsheet math and common convention; if you pay down your mortgage you are effectively making that interest rate on your money. 

You did not specify the age of the property so it is purely speculation at this point.