We booked an 11 night cruise from Sydney on RCI's Voyager of the Seas. The ports included Auckland, Tauranga, Napier, Picton, and Wellington. We've used Carnival and Disney in the past. Overall we really enjoyed the trip. Between the 3 lines we rate Disney as #1, RCI as #2, then Carnival as #3. The prices we paid more or less matched those rankings, so I guess you get what you pay for.
Our room and cabin service was excellent...the steward went out of his way to greet us by name and open the door for us as we came "home". He never failed to ask if we needed anything.
We were disappointed with the spa...my wife paid for a five item deal and they attempted to only perform 3 of the 5 services. They did rectify it, but there wasn't a good reason that it was ever an issue. Also the services were overpriced and even when she went ahead and purchased services they spent a lot of time trying to upsell her on more expensive add-ons.
We had little to no complaints about our room. The promenade view did not really add much value, but we were in the back of the ship. Someone in the middle may have had a better experience with their view. We had two adjoining rooms, one for the kids and one for my wife and I. Between the two rooms, there was more than enough space for the whole family.