From my friends, who worked F-15s and now work F-22s, they say early on, F-22 was a pain. Now, the kinks have been worked out.
And the Raptor is more maintenance friendly to the ground crews than her predecessor, the Eagle.
The PW F119 turbofan can be easily repaired with any one of six common hardware tools.
A PMA (portable maintenance aid) computer is plugged in and out of a socket in the Raptor, diagnosing any faults for repair.