From the beginning Ive told people this project was a piece of crap. Russia has been spinning it around air shows trying to convince the world its very first attempt at stealth has jumped three generations ahead of the Yanks.
And then each time west becomes surprised how did these russkies created such a deadly plane
- MiG-15 - oooops big surprise
- MiG-21 - oooops apparently it is great plane, encounter it - go low and run for your life
- MiG-29/Su-27 - ooops apparently they one of the best short range missiles and helmet mounted sight and absolutely deadly in close combat (it took about 15-20 years to west to get such stuff)
Ahhh one more... another wooden wonder around is La-5/7 - BTW top ww2 allied ace Kozhedub had flown this wooden wonder.
I always wonder when West would stop consistently underestimate Russian designs. I assume that Chinese would finally have their plane that does not fall far from western but cheaper and in greater numbers.
I'm not telling that Sukhoi PAK FA is not in problem especially after Putin puts hist own country into economical death spiral.
But yet forgetting history is something very-very common

Look at the problems were having with the F-35, our 4th stealth airplane.
The problem with F-35 isn't its stealth. But rather an attempt to design 3 planes in one by a committee, push every possible and impossible tested and untested technology call everything else obsolete and finally not doing proper risk management.
Take a look on F-117... Have blue had flown first time in 1977 and in 1983 F-117 entered service (6 years from the concept design to service) and F-117 first flight was in 1981(!).
It was good design that concentrated in a specific task.
What F-35? Is exact opposite, no wonder it didn't "fully take off" yet.