Once it's in service, the branches and countries flying it will figure it out, how to use it and how to improve it. Just takes time and money and more money.
The F-22 is a big leap beyond the F-15. The F-35 will be an improvement on the AV-8B and it has supercruise, unlike the F-18 and F/A-18. It has stealth and computer power over all of three and much easier maintenance, but is it a major leap better at doing the job it needs to do? We'll have to wait and see...someday...