Mitchell, SD
I have most of those games and location. My mmr earnings have also dropped. Out of your list that you have I would easily say that Metallica Pro ranks near the top for earning.
3 reasons it earns well consistently.
1. Simple rules for beginners. Shoot the middle and get multiball and points
2. Deep rule set for more experienced players
3. Most people love Metallica and will drop coin just for the experience.
Those 3 things make it a well rounded game that earns great.
That being said it would be one of the last games in my house haha!
Any game that involves shoot the toy get the points typically earns well. Afm, mmr, Stern Star Trek and Metallica.
Top consistant earn for me is addams family.
