I have recently been to both Galloping Ghost and the Underground Retrocade. Here is what I thought of the machines at both:
GG -
Freddy: Nightmare on Elm Street - out of order
Pinbot - out of order
Black Knight - upper left flipper is out of order
F14 and TZ - both players condition, playable
Gorgar and Space Invaders - both games basically set to zero incline. Ball rolls so slow you literally get bored. Could play forever, so I guess that's "good" news.
Funhouse and Creature - two most popular machines there. Creature is missing, literally, as in when you light up a letter in "FILM", he doesn't appear. Doesn't effect gameplay. Funhouse is also playable, but Rudy is cross-eyed!
As for The Underground, here were their machines:
Black Knight - flippers aren't powerful enough to get the ball to the upper playfield. Unplayable without that if you ask me.
Dungeons and Dragons - impossible to get it up to the dragon's lair on either side. could be a fun game if it worked 100%.
Space Shuttle - again, flippers don't have enough juice to get the ball up the center ramp.
Johnny Mnemonic - best game there. Everything worked 100%, even the glove!
Bugs Bunny - solid game. Fun. The flipper in the lower playfield was all jacked up, but was okay I guess.
Fire! - I played this one a lot because it was fun, bit it also suffered from weak flippers. I was only able to get the ball over the jump and into the window once. The other ramps were also difficult to traverse, but I still enjoyed it.
Comet, Eight Ball, Xenon, Blackout, and Laser Cue - not my style, so I didn't play them that much.
In summation: More does not always equal better. These games need a thorough work over by an actual technician. Both places cost $15 for all day access. Not worth it if all you want to do is play pinball, in my opinion.