I'm not an expert on the Royal Jordanian program but just a couple of thoughts:
- Firstly, "oneworld gold" doesn't actually exist, as the definition of 'Gold' differs between airline frequent flyer programs. I presume you are referring to Qantas Gold and Royal Jordanian Gold, which both equivalent to the mid-tier oneworld Sapphire level. In comparison, British Airways Gold is equivalent to the top-tier oneworld Emerald while American Airlines Gold is only low-tier oneworld Ruby.
- While RJ Gold does appear to have the easiest oneworld Sapphire qualification requirements it may depend on the routes and fare classes you intend to book. You may find RJ won't give as much mileage credit for your flights compared to other programs. In this case, it may actually be easier to achieve qualification with a different program (for example Air Berlin or American at 50,000 miles).
- Some programs also have a minimum flight requirement, such as Qantas which requires at least four flights annually with Qantas or Jetstar. I'm not sure if RJ have a similar requirement.
While The benefits offered by each program are substantially similar (i.e. oneworld Sapphire across all airlines will provide similar benefits regarding priority checkin, baggage allowance and lounge access), but may differ at the edges which impacts which program you wish to select. For example, holding Qantas Gold gets you into Qantas lounges when flying Jetstar; holding Cathay Silver (oneworld Ruby) provides lounge access at Cathay lounges when flying Cathay or Dragonair.
Specifically comparing advantages / disadvantages of the Qantas Gold tier against other oneworld Sapphire programs, my thoughts:
+ Lounge access when flying Jetstar and Emirates, which you will not receive holding Sapphire status with another oneworld airline
+ Status bonus points when flying Qantas, Jetstar or American
+ Upgrade priority (I believe Qantas prioritises its own members over equivalent status holders from other airlines, but am not sure)
+ Points are easier to obtain through partners if you're based in Australia, which reduces the risk of having orphaned points with another airline (that expire but you don't have enough of to use for a redemption)
- Points are less valuable compared to other programs (i.e. you need more of them, plus cash co-payment for redemptions)
- Loss of potential other valuable benefits (e.g. lounge access at Ruby level with CX, system upgrades with AA, etc. This will depend on what you value from your program)
Hope this helps in some way.