there is really one one working girls bar...it wont be hard to miss. older gringo tourists men outside...and well..nearly all girls inside. it is seedy...but i wouldnt call it dangerous.
The rest of the street is pretty quiet...with manly euro's and families hanging out till about 11pm.
As a single tall 40 year old guy i have never had problems getting to my hotel in the middle of the night...are you traveling solo? IF you are traveling as a single woman i would exersise some caution getting back to your hotel at night. Not sure exactly where it is located. If you are traveling with a friend or two...not a problem at all.
For eats...Fernando's...it is near the central parque...turn the corner on duarte and its right on the left. Nothing fabulous...but good traditional food and very reasonable prices (get the camarones creole...but make sure to ask for the camarones grande). Decent pollo guisado, pescado frito etc.
another good budget bet is the german place right in the middle of duarta @ plaza bonita. Pizza for two is a not a bad deal...and the pizza (while not to NYC standards) aint bad. They serve a decent breakfast as well. (a simple pork loin dinner tho took nearly 3 hrs from start to finish...ahhhhh...dominican waiter service!! lol)
if da nancy (behind the hamaca) is still around...decent italian...a little pricier...but very good (get the rice with seafood).
Not sure if Neptuno's is worth the price (i hear around 40-50 usd PP). I am just very fussy when it comes to food...and for that price i am going to expect something exceptional. I hear it is quite good tho...but i am a frugal traveler
good luck! and be sure to give us a brief trip report when you get back!