ATT next program?

can someone explain in detail why the Next is a good program?

I heard 1 guy in line say its horrible then the employee tried to convince me to switch to next because the 2yr method is soon out the windows and iw as reluctant to switch to the next because he didn't give me more than 1 reason which is i just pay taxes up front lol.

anyone have a good understanding on the differences between the two?