Hilton Honors quick guide
Hilton Honors has plenty of points earning options including the ability to earn 10 points per US dollar spent with Hilton Honors, and frequent flyer points simultaneously. Alternatively, the double-dip feature allows you to opt in to earn five extra Hilton points (15 in total) instead of frequent flyer points. Generally speaking, the airline points redeemed are of less value than the Hilton points. Hence in the points calculations below, we will assume you are double-dipping.

There is an exception. Looking at the rate at which airline points are awarded, Qantas and Krisflyer are one point per US dollar spent. However, one interesting quirk is that Virgin's Velocity earn rate is two points per US dollar spent. Even if you want Krisflyer points, nominating Virgin then transferring the points over to Krisflyer from Virgin at 1.35:1 will mean you earn 1.48 Krisflyer miles per dollar, close to 50% more points than a direct transfer (be aware that a transfer from Virgin to Krisflyer requires at least 5,000 Virgin points).

In brief
Points earned per dollar: 15 per US dollar using 10 base points plus 5 using the double dip option, which is 11.25 per AUD (at $1AUD=$0.75US)

Points earned per $A300 night: 3,375

Points needed for a free night at the same hotel: 60,000

Number of nights needed to earn a free night: 18

Benefit as a percentage of spend on room only: 5.5% benefit for staying 18 nights at the same hotel: 14% per night which is made up of 1.8 free nights at $A300 per night, and $216 in cash: $756 in total.

Advantages: small discounts for joining and booking on the Hilton site (~2%), free Wi-Fi, options to earn bonus points during promotions. Two Australian credit cards gain automatic Gold Hilton Status: Macquarie Honors Visa Card and American Express Platinum Charge. Gaining Virgin's Velocity Gold status allows you to choose Hilton Gold status as one of the options (IHG is the other option but offers very little in terms of benefit). More benefits are added as you gain higher status levels.

Disadvantages: Hilton Honors points are calculated in US dollars. This effectively cuts the earn rate to 11.25 points per Australian dollar. Points expire if there is no activity in a membership year.

The calculated number of nights you need to stay before you earn a free redemption is quite high and will be less in practice. You will most likely bump up to the higher loyalty tier of Silver before getting enough points for a free night. Silver requires either 10 nights or 4 stays before you get the status bump at your next stay. Silver earns 15% more on your base spend (337 extra points per $A300 night), bringing the number of nights down to 17-18 depending on how soon you get Silver status. If you stayed those 18 nights in a row, you will get no bonus until your next stay as status is applied after you check out. Conversely having four single night stays will get you there quicker, bringing it down to 17 nights before you get a free night.

For an overview of the major hotel rewards programs, and which offer the best value, see Which hotel loyalty program should you join?