That’s the kind used here (Pierce County, WA). As stated, it’s simple, (relatively) foolproof, and fast at recording, which means that any number of people can be filling in their ballots at the same time.
Another advantage is instant—or at least quick— feedback. Shortly after the system was introduced, the reader spit the ballot back at me (turned out that I’d inadvertently made a stray mark that made it seem as if I’d connected two arrows for the same section). The poll worker destroyed the spoiled ballot in my presence and issued me a new one.
Here’s a bit of trivia: In the U.S. in the 19th Century, voters were not provided with preprinted ballots with boxes to check – they were expected, instead, to insert in the ballot box a paper with the names of their favored candidates written on it; but the parties helpfully provided them with ballot slips preprinted with the names of their whole slate of candidates. To “vote the Republican ticket” meant to put one of the Republicans’ preprinted ballots in the box.