Once equipped, the Su-57M will be the first 5th generation fighter that can super-cruise at Mach 2, not to mention its 3D thrust vectoring capability.
With the exception of stealth, there is nothing quite like the Su-57s in the world, which reflects an interesting approach towards next generation air-to-air combat capability while everyone else is prioritizing on stealth.
The sub-sonic F-35s may have the stealth, but once detected, the Su-57s will be able to chase them down at twice the range and twice the speed, closing in on them at 700km/h. At which point, the F-35s are practically sitting ducks once their covers are blown.
Interestingly enough it looks like it's stealthy enough for practical purposes. It definitely looks like they made the right compromise with stealth to retain actual maneuverability.
The Russian Air Force has demonstrated high confidence in the Su-57’s stealth capabilities, and has deployed the fighters for high intensity combat operations to parts of the Ukrainian theatre with particularly high concentrations of Ukrainian air defences.
It is very stealthy compared to 4th gen fighters like Su-35s, but still has RCS far worse than, say, an F-35.
Depends on who you’re listening to, there are experts in military aviation who believe that sensors and detection algorithms will eventually become so sensitive that the huge advantage of stealth could be rendered obsolete. In which case, thrust, maneuverability and firepower win the game. Like if you’re F-35s, once detected, you cannot outrun or outgun the Su-57s. You’re dead.
It's highly unlikely that there's no possible method for detecting stealth craft, so if the problem hasn't been cracked then it will be eventually. Betting everything on stealth seems like a deeply flawed strategy to me as well.
The Su-57 program has prioritised reducing maintenance needs and operational costs to avoid the very low availability rates that have plagued America’s F-117, F-22 and F-35 stealth fighter fleets. One notable means by which this had been achieved is through reduced reliance on radar absorbent coatings, which was achieved by using innovative solutions such as radar absorbent fibreglass. In contrast to American stealth fighters which consistently cost far more to operate than their fourth generation predecessors, this approach allows the Su-57 to potentially achieve lower operational costs than its direct predecessor the Soviet Su-27, thus allowing Russia to move its fleet into the fifth generation without either significantly raising sustainment funding or contracting the number of fighters in service.