The Central Highlands route is still considered way off the beaten track; you'll encounter few English speakers and will need to brush up your Vietnamese (or acquire a phrasebook). It's a rewarding experience that can astound and inspire.
stopovers, rather than as destinations themselves. Even the larger cities like Buon Ma Thuot offer little in terms of traditional tourist comforts, such as a selection of restaurants with English menus, and few sights to see around the city. These cities can easily be explored once you arrive merely by driving around and pulling over when you see an interesting church, monument, or memorial.