I used to go to the location at the Borgata and I'm so happy they opened something closer to me! I have been to this location twice. Both times for an all-over color. I was supremely happy both times. I had my hair botched (dyed way too dark and she missed a spot!) at a midtown Phoenix salon and finally my color is getting back to normal. I have an appointment this Thursday for a partial highlight and locks of love haircut (which they do for free, the only high-end salon I know that does this).
I can't speak about their nail services, but I've also had facials at the Borgata location and they are amazing. They even shampoo/style your hair for free after so you don't walk out looking like a hot mess. I've always loved Dolce and received great service there (aside from a facial three days before my wedding - the aesthetician didn't tell me this was a BAD idea), but hey, you can't control all of your employees all the time, and I went back several months later for another facial and the aesthetician apologized for the other girl's error.
I have always loved Dolce and will buy a membership when I can afford to get services on a regular basis. In the meantime, I (and you should) keep an eye on Groupon and Living Social for deals, and they also give you 25% off services during your birthday month (I don't think you can combine the two discounts).