Nice to have an option you don't have to use, but can without taking the rest of the day to get back up to fighting speed.
Agreed. And the new (higher thrust) engines will reportedly improve the already stellar ability to regain energy, improving that option even further.
Clearly, the Russian designers have a different philosophy and thus have taken a different approach and emphasized different features than the designers of the F-22 and F-35. And that is largely because USAF has decided to put so many oof its eggs in the stealth basket. It'll be interesting to see which philosophy (stealth vs super maneuverability) wins out once the T-50 is fully developed, goes into production, and starts flying against F-22 and F-35.
And speaking of production, the Russians and Indians don't seem to be enamored of concurrent engineering. It appears that they're building test aircraft and fully wringing them out before committing to production. Yet another philosophical difference.