Su-57 looks like heavily modified Flanker design. It's almost like Russia didn't have the budget for a new design from scratch so they just heavily modified Flanker frame design and came up with Su-57.
It also doesn't look very stealthy. I seriously doubt it can rival F-22 or F-35.
It is partly true what you said, the PAKFA is designed to be more economical, to operate and make, it is designed to be more reliable.
Russia is a huge country, and today`s economy is relatively small, thus they need a very very economical engine, 117 is not that economical, type 30 it is supposed to allow long trips economically.
PAKFA has been designed with good frontal stealth, excellent maneuverability, good supercruise and max speed why?
Stealth for starters does not mean it is undetectable, Rafale and Su-35 already have IRST systems that very likely can track F-22 or F-35 in the 90-100 km range.
However weather can reduce that range.
PAKFA has been designed to jam the enemy missiles and out run them.
So it is Rafale and Su-35.
all these stealth fighters have limited weapons bays, and missiles do not hit 100% of the time their targets, specially if their enemy flies fast.
What does it mean, in the Russian philosophy dog fighting will not go away from history.
remember F-22 only carries 2 sidewinders, once they are gone it needs the gun.
what happens when you have a very expensive machine? first you buy less, only 190 F-22, they fly less, at a flight time of USD $30000 dollars well you can not expose them.
In close support visual identification is crucial, because of fratricides, mobility and the fact at close range both F-35 and F-22 are not stealthy, they are not suit to replace A-10.
the first problem is speed, F-35 will have less accuracy, second is loiter time, they can not fly long small bays means small fuel tanks.
and the stealth coating makes them unsuitable for the close support mission.
The Americans have been duped, F-35 is the new F-111 and new F-4, but in reality PAKFA can not do close support too.
So what you get is a fighter that needs to fire from long distances, so it gives plenty of time to scape to the targeted aircraft and enough time for the rocket to reduce its ability to chase.
In real combat situation, F-22 and F-35 stealth philosophy is impractical.
Thus PAKFA was designed for the Russians with enough stealth but with a more affordable philosophy in mind in their way of think