it will save around 25-30 minutes in both direction already 12049 Agra hamesha 15-20 minutes early hi pohchti hai.
But to be honest trains like Taj Express, Mangla Lakshdweep, Punjab Mail, Swarn Jayanti, Samta, jaisi trains ko iska fayeda milna chahiye.
Taj being a superfast train takes roughly 8 hours to complete it's entire journey.