I didn't know this, but the F-35 Lightning II is widely considered to be the most expensive weapons defense system in history. It is massively over budget (almost double what it was said to have cost) and over 7 years behind schedule. And even though it is now cleared for combat, some say it still doesn't hold up to the capabilities and maneuverability of the aging F-16.
For all its cool features (like vertical liftoff, for one), it's hard to say whether this was worth all the time and money.
Here's a neat video of it in action.