We will never know the full scale, because that’s classified, but there are some details that we do know, and some that are reasonably safe to assume.
Sensor systems better than anything else fielded (confirmed due to the high cost of one particular part needed for an IR tracker and camera)
Teaming possibility with other planes where one plane detects and another plane fires
Exceptional radar
An unknown quantity of EW capabilities
In addition to this, I’d like to point out a major difference between US arms industry and that of russia: US capabilities are usually understated. Russian ones are usually either overstated, or only possible in the most ideal set of circumstances.