This baby has come a long way since the first beta. And an exponential leap from 10.8.X. Smooth, efficient, shuts down almost instantly, boots really quick. The multiple display adaptation bothers me a little though and needs some refinement. You can't drag an app window to the edge of the screen and have it shift to the next adjacent desktop with multiple monitors. I'm pretty sure this is permanent. Maybe it would be too confusing? Anyone else bugged by this? Otherwise, except for a few other small glitches, Mav's is looking solid.