F35 Stealth Fighters.

Like anything else, cars included, when the technology is cutting edge, the problems are numerous. About the time the bugs are worked out, the product is obsolete. Those who stuck around to work out the bugs will have fond memories, while those who only saw the problems without the fixes will likely curse it forever.

When the USAF began flying F-16s, the Canadian Forces interceptor mainstay was the F-101, a post Korean war design. They were reliable and inexpensive...and fast...but limited in their capability. They served Canada well, but would not have been capable outside of their NORAD mission.

The wisdom, or folly, of buying a new aircraft design is a judgment call based on a political view of the Australia's future military role in the world, and there really isn't a more capable airplane available if that role requires the best.

C130 Chief makes a good point. In the 1960s, the TFX was cancelled because the Navy needed heavy landing gear and folding wings for carrier operation, while the Air Force wanted a lighter airplane that could fly farther and longer, and carry a bigger bomb load. The expensive compromise satisfied neither service. The mission should dictate the design, not vice versa, so with the long lead time to design and develop weapons systems, the politicians better be very sure of future missions.