Scenic's 5 star luxury river cruises are well known and popular in Australia (not so much in NZ). Scenic were the first to introduce balconies on their Scenic Space-Ships, which many clients love, but this comes at a cost to interior cabin space. Like many of the other premium river cruise Operators, look out for their great Fly Free offers, and Earlybird Savings. All inclusive, with Freechoice activities that allow you to choose what you want to do in each port, Scenic also offer a range of luxury additions (like your own Butler) depending on the cabin type select.
If you are looking for 5-star luxury with 6-star service then Uniworld river cruises should be at the top of your wish list. Uniworld's ships (while not the newest) are one-of-a-kind, exquisitely appointed, boutique floating hotels. Part of the Travel Corporation (which includes the sister brands of Trafalgar and Insight Vacations), Uniworld ships are slightly smaller with an average of about 130 guests, and are constantly being refurbished in their distinctive style. Half of the team at Global Journeys have embarked on a voyage with Uniworld and some us a few times!
Uniworld pricing is now dynamic so can vary day by day, and the cruises aren't cheap, however you wont need to dip into your wallet once your trip begins and further savings are available if you were a past passenger on any of the aforementioned sister brands.