I'm using standard flipper rubber.
The thing is that there are so many tiny differences in how each game is assembled one person may or may not have the same issue as the other. All I know at this point is with the bracket I get mystery rejects but without the bracket I don't. I've moved that thing back and forth a million times and it's the same result for right orbit shots. Moving it does change my left orbit shots though.
heck, when I first opened my game I could barely shoot the right orbit due to my right ball guide being bent out ever so slightly. I took it off and re-bent it to now have a nice flow/curve and the right orbit now works smoothly.