I still have the slide as default and use it a lot. I have it set to slide when I mousewheel on the desktop and keep my taskbar shorter so there's always some desktop showing in the corners. When I get frustrated with something though, I hit my key to activate the cube and the animation of it pulling away from the normal view works as like a disconnect from whatever I'm doing. Virtually stepping back basically.

Without the cube, I found I would get frustrated and instead of working on something else I would keep going and ultimately make mistakes and end up more frustrated. If I tried switching with the slide or fade to another project, the irritation stayed with me and I'd mess those other projects up too. The cube, for me, just worked.

I did have some success using the overview, however it was a lot more overwhelming with the way it shows everything, while the cube limits it to what's on each cube face, without showing minimized windows at all.