By my reckoning, all over in 19 minutes! It was a potent combination of a recklessly fast leiner, and a strict no boo-ing policy. Usually, I have one without the other, but here there was both! Awesome.
Incidentally, before the leining began, the gabbai gave a short speech, admonishing everyone not to bang when Haman's name* is read. He told everyone that it was pretty selfish of people to make noise during the reading, as the whole point of the non-booing policy is to ensure that we can all hear every word. This was pretty funny, as that was most assuredly not the real reason we were all there.
The way I found the minyan was by following all the bums and unmarried people, and all the old people who don't give a ****, to the minyan where I knew there would be no children. We weren't there to hear every word (and I'm pretty sure the guy was so fast, I didn't hear everything anyway - yay!), we were there to go fast.
To me, it's not so much the amount of time it wastes, as it is just incredibly annoying. It just totally breaks up the narrative every six seconds. It's like reading a book, where every time the main antagonist's name comes up, someone shoots a cap gun two feet from your head. But I like the idea it makes me more religious because I irritate easily.
*His name is "Haman"!