Nobody understands the ruleset.
It's crazy.

Seriously though, rumoured to be Sterns best selling game.

So no, not over-rated.
Still, might not be a pin you enjoy, which is cool.

It's not under-rated where it counts most; Stern made a ton of cash off this one. Obviously it will influence future pins.
The top 100 Pinside list is a joke.

WRONG!
ACDC has 5 MAIN shots in it, but there are also the three sets of target banks, and the Lightning bolt targets. What really makes this pin shine though is the fact that most every shot can be made from either flipper. There are so many options to aim at with every shot, it's silly.
Those who flail away at the ball will not enjoy this pin. It forces you to catch, nudge, and aim each shot. That's the beauty of it. So many options, so little forgiveness.

Are you talking drop targets, or the Lightning standups.
Try hitting the stand ups when Thunderstruck starts and the target is moving back and forth.
There's tons to aim at on this pin.
One thing that makes this game really shine is that you can play it any way you want. Shoot the ramps, go for Jam Multiball. Hit targets, go for Album multiball, loops for Tour, etc.
Or qualify your song, then nail the five main shots, and keep em going to build the song jackpot.
Or... Hit all the areas on the playfield so you can move to the next song.

There's so much more to this game than only 5 shots.

I have to disagree with this. What I love about ACDC is the flow. Players are encouraged to shoot combos, and that keeps the action fast and furious. If you shoot the left loop, and the ball comes all the way around to the right flipper, you can take a fluke smack at it, and sometimes drive it all the way around again, even faster. Sometimes even more, though I think I've only done this about 3 times.
Yes, the combos are a software thing, but it wouldn't be possible if Ritchie hadn't made a crazy smooth table.

This isn't a game with any stop and go. Even Metallica (my second fav game I'd say) is a little slower as you hit things that stop the ball quite frequently.

Still, as far as great-multiballs go, ACDC is the king.
I do have to say though, that the bridge crossing in LOTR is also spectacular.

Sounds like your wife is all the protector this pin needs.
: )