Quoted from Coyote:

Catches the ball, like the other two magnets!
Seriously, in short, it:
(1) During 'The Spiral' mode, it will stop the third ball shot up the Spiral.
(2) Most importantly, when the game knows the powerball is in the gumball machine, and Multiball is started with two or more balls at the autofire kicker, starting multiball will cause the game to catch all three balls on the spiral magnets, and then release them all at once.
Original design had the above, plus the ball toss for balls still in the lock. However, Ted Estes found that the reliability of tossing the balls like that was too difficult and too prone to failure.
Had he been able to get it working, it would have looked like this:
» YouTube video

Quoted from Coyote:

And this is why I do not like you.
Whike none of your facts there are incorrect, you apparently just came in here to post this without reading the entire thread. Apparently, just to chime in that you 'know something'.
You obviously haven't read the threaad, or heaven forbid, even looked at the effin' pictures.
So, here, I'll spell it out, for those that are curious -
Yes, it IS an early sample. The mods are mods, and have nothing to do with that. (Samples didn't have a 'piano', or a 'slot machine', 'rocket', or 'car' toy. Never did.)
So, first clue? A really EASY and SURE-FIRE clue? Look at the left ramp lights. In early sample games, they were bordered by a green rocket artwork. This was changed later to white. Mirco's reproduction 3 magnet playfield art did NOT HAVE THIS. So it is not a repro from Mirco.
Second clue? Look at all the T-nuts on the underside of the playfield. Almost every post had one. They changed this to a locknut around my game time, because the posts would loosen in the t-nuts. Mirco's repro sample plaufiel did not have the recesses for the t-nuts. The early samples did - even if like in mine, t-nuts weren't isntalled.
Third clue? Look at the piano light board. Noone - that I know of - has EVER reproduced a board like that. GLM made a 'flasher board', but it's LED, not incandescent. It's pretty identical to every other lamp board out there, yes? But look at the four large door panels. THIS board has a space for TWO add-on flasher boards - top AND bottom. Everyone else (including me) has one (top).
There are other clues, as well - the 8-high-power driver board. It has 6 populated slots. And while the 3rd magnet add-on /mod populates this spot, look at the wriing running TO the board. it's not added on after - it's factory. And the metal ball guide for the 3rd magnet. That's not a drill hole, since the opto is screwed TO the metal guide. That opto was not 'added on afterwards'.
Other non-pictured things would be the 2x 7-opto boards. Yeah, someone could completely rewire their game, but it wouldn't look factory, and because of all the above, I'm willing to put monet down that it looks factory as well.
So, I ramble. In point, next time you spot off about stuff, you may want to read the thread and look at and study pictures before claiming someone just 'modded' their game. Or, learn ABOUT the game (all my info above has been posted elsewhere, and by others in the past) and learn what to look for before spouting off.