Sorry, you don't have a slightest idea what you are talking about. Russia now has no more than an empty flattened tin barrel they call T-50. In no way it is a 5th generation fighter. It is not even a fighter yet (no proper engines, no radar, no avionics, no weapons). And even this empty can cannot fly. Out of three "prototypes" one is already broken and is cannibalized to allow imitating test flying to a single plane.
F-35A is in a low production rate state now. The end of testing is visible now. Yes, some ultra-fancy gadgets like the mentioned helmet visualization system require improvement, but none aircraft has these gadgets anyway.