I’ve owned both GOTG Pro and Iron Maiden Pro. I still have Iron Maiden...
GOTG is a more fun theme in my opinion but gets boring. Run through 4 modes, start Cherry Bomb, try and make it through the other 4, maybe start Immolation. Gets repetitive.
Iron Maiden has a lot more going for it IMHO. The shots are more fun, the rules are better and less repetitive, but I’m not a fan of the music. Pin is gorgeous because Zombie Yeti.
I suggest saving yourself the cash and grabbing IM IMHO.