The Proton Mod is really just a fun mod that makes the game more playable and enjoyable as one down side is, it can be a drain monster and then not a fun game to play at times.
My kids - 8 and 12 did not play GB much as they hate the outlane drains and centre drain. After designing and adding the mod, the game has become more played and everyone has gotten a little further in the game. But if there is a comp on - simple turn the mod OFF at the coin door and everyone is on the same level - there is choice.
Out of interest I did a stats audit before installing the mod:
LHS Drains - 17.5% - 229 times
Centre Drains - 62.2% - 855 times
RHS Drains - 17.3% - 227 times
Then after close to 300 plays with the mod the stats were:
LHS Drains - 12.8% - 273 times
Centre Drains - 73.8% - 1569 times
RHS Drains - 13.4% - 286 times
So yes they come in handy and the length of games increased slightly but the game is more fun.
There is alot going on watching multiple balls especially in a multiball so you do miss stopping the ball at the sides and now it is 2 hands and a foot to play the game - there is still challenge in the game.
But what I noticed most is my kids love playing the game and playing more and their flipper skills improved due to playing the game more and then the proton use reduced a little so it helped improve skills. It is actually a skill to use and their is a function on the servo driver boards that you can modify so when a switch is activated it goes to the max point and straight returns to the rest point so timing becomes more critical. I haven't beaten the game but it has helped some of my games last a bit longer.
Lastly my 8yr old soon now has Grand Champion in the God Mod which is stoked and has one over me.