In ninties, we use to have Mig-21s escorting Jags for strike. Yejas does the jb of one such combo. so It is surely much more than Mig-21Bison. Plus it was adjudged to be the best in air to ground targeting by IAF in recent wargames.
How does it compare with respect to reaction time. That is from alert to scramble to reaching target interception altitude wrt to the Bison and Mirage?