From Agra, There is no evening departure train to Lucknow so if anyone needs to reach Lucknow in night, he needs to take bus. There is no proper connectivity to catch Rajdhani gang at Kanpur as well since Gomti is neither reliable nor anyone get reservation in that.
Same things happn in return direction also, there is no morning departure from Lucknow to Agra and passengers coming from Rajdhani gang in the morning also had to travel by road till Agra(Sometime they take Shatabdi till Etawah but after that also they...
more... need to travel 120km by road).
So stoppage at Tundla will definitely make those salient who feels that private trains are not successful.