Melia Nusa Dua is great. From first arrival it feels luxurious and imposing, whereas the Balinese (and other) staff are polite and friendly without fault. We stayed in two adjacent ground level rooms that open up on to semi-private pools, one for us and one for our 3 teenage sons. It looked like luxury to them, and a bit like a villa to us, which was a win all around (they didn't fancy hanging out at the pool with lots of other little kids).
The buffet breakfast was great, although you settle into a groove where you don't go too silly with food. There are other good dinner options within a walk or quick taxi ride nearby.
Only two other things to say:
- in some parts the hotel looked it's age (i.e. not brand spanking new), though not a problem unless you're really fussy
- Nusa Dua is a bit of a trek to some of the other places you might like to go in Bali, like the beaches near Uluwatu, or Kuta/Seminyak, or Ubud. Taxis are pretty cheap, and the hotel can organise them for you, but if you want to go out, you have to bear that in mind.
I'd go back to Melia though.