Anyway....
The mower came out of the box in "mulch" mode, but converting to "side discharge" takes seconds: lift a spring-loaded door, insert chute, release door. I cut a single 20' strip of grass and decided no, I was not doing to do this in "mulch" mode, as it would take entirely too frickin' long. Even The Awesome has its limits, after all. So I shut the mower off, got the discharge chute from the garage, and put it in.
...and then I proceeded to cut the extremely long grass at about the same speed I would normally cut the grass, without having to slow down much at all.
Awesome.