Mao is nice and hasn't yet been overrun by tourists.
It has Agua Azul, maybe the nicest swimming pool in the country, with a bar and band sometimes.
The Miss Universe of dams is nearby, with a gorgeous lake and good fishing (hook only, no spear fishing allowed).
Mao is EASY to reach. Express buses leave for Mao every 30 minutes from 2 different rotundas in Santiago, arriving about 45 minutes later. They go through Navarette without stopping, but DO stop in Esperanza. In Mao, they stop at the central park, which is very nice and convenient. The non-express buses stop in Navarette (or anywhere else) as well.
Hotels might be the biggest problem (if that's the right word). Agua Azul (with the swimming pool) is nice and only a 10 minute walk from the center, but is expensive for a non-tourist area (possibly as much as 1000 pesos). There are also tiny hotels, almost boarding house like, not too far from the center and very cheap (300 pesos or less). As you enter Mao, there is a fairly modern looking motel on the right, named Cajoba I think. Cheap, probably less than 500 pesos, but used to have plumbing problems.
If going by car from Santiago, I think that it can even be done fairly safely at night, because there are houses almost all the way. I wouldn't drive at night west of Mao though, toward Santiago Rodrigues (Sabaneta) because there are vast empty stretches.
BTW, it's NOT especially hard to find the way from Santiago. Going NW on the main drag, Las Carreras (from the direction of the Capital), veer right as you approach the Yaque River (you don't cross it until you're approaching Mao). After that, you keep to the left (twice, I think) until downtown Esperanza. There you make a 90 degree right turn toward Mao. You can easily ask if you need help for that one turn.
Mao is fairly good sized, with about 50 thousand people. It has almost anything that you'll need, mostly within a 10 minute walk of the center. At the same time, you'll be seeing the REAL DR.
BTW, there does seem to be a lot of pretty girls there.