Power to the People
The development of a lot in a new subdivision typically includes bringing all utilities onto the site, where the new house is easily connected to them. Electricity, gas, water, and sanitary sewer services are available at the edge of the property, ready to be used.
Undeveloped property won't have water and sewer taps on site. In fact, there may be no utilities anywhere nearby. Building on undeveloped land usually means providing your own private septic system and water well, installing a propane storage tank for gas appliances, and bringing electric service lines in from a distance - maybe a very long distance.
Can You Dig It?
By the time a subdivision is ready for construction, the developer's engineers have tested the soil and graded the land for proper drainage. You'll have access to information about the possibility of sub-surface conditions that might affect your construction plans and in many cases the developer will take some responsibility for the site's suitability for building.
If you want the same information about your rural property, you'll have to order and pay for it yourself. Your county extension service can provide some of this information but it may not be recent, or specific to your site. If you discover bad soil or underground rock in your building area, you'll have no avenue for redress except your own pocketbook.
More Than One Kind of Value
A house in a subdivision may have a temporary price advantage over a "stand-alone" home, since its value will be related to the selling prices of other homes in the area. If you value predictable price appreciation, closer neighbors, and want less "hands-on" involvement in the creation of your house, you'll probably find your dream home in a development. The majority of American home buyers do just that.