I think the pop bumpers in Stern SW are implemented well. If you can nudge and keep the ball in there, you get increased scoring or bonuses or activate things. Also, while you can't see which upper lane the ball will hit when going up, you have to pay attention in order to hit flipper for the way down so as to get as many lit as possible in order to increase scoring multipliers (and maybe more, the game is new to me).

Also LOTR bumpers play into game also. You have to get some number of pops in order to get Boromir to join the fellowship. Also, same issue as SW - you use pop bumpers to get ORC lanes lit as much as possible for scoring multiples.

And as notes, Beatles pop bumpers collect members and knock down 1964 drops. Also, there is a mode that has increased scoring for pop bumpers, and it pays to keep the ball in the upper playfield.

To the OP, I've played pinball on and off for a long time and understand kickbacks are cool. But in the past year that I've become a more serious player (or at least a member of the hobby), It doesn't matter to me if the save is a kickback or ball save that comes out of the plunger. Game play is just different for that model, not "changed" (IMHO).