Stereo is for smaller spaces unless the event needs stereo for effect, but only briefly. Large venues have areas where the 'other speaker' isn't audible at all, so achieving stereo in a way that doesn't screw it up for others is difficult.

There's also the perception that 70V sounds bad- it's can, but doesn't have to. I did an audio upgrade for a school gym system and used JBL Control 26D in-ceiling speakers, a Control SS2210 sub, Soundcraft EPM-8 mixer, Shure wireless mic and a Crown CDi1000 amp- if I could have replaced the back boxes, I would, because they weren't made for these speakers, or even the old Atlas speakers that I replaced. They were too shallow and the baffle had a gap at each end, but they were installed with conduit and the cables passed through most of them, so I put some strips of thin plywood over the gaps and used the original grills to cover them. Since the low end was cut off and they're about 24' from the floor, it wasn't as much of a problem as it would be if they were lower and used for full-range.

Everyone who I spoke with after it was done was happy with the sound, some were impressed- probably because the old system sounded like a pocket radio.

And I did speak with Fred when I was choosing the mixer- he was OK with the rest of the equipment choices.