I have to admit I still like and use the Compiz cube, but what I really like is the Wobbly Windows effect. It may seem cheesy to many, but it's oddly satisfying to me. And it's really smooth even in VirtualBox.

I love my wobbly windows. It's an effect that you can only do on an open source desktop. I don't doubt that Microsoft or Apple could implement wobbly windows if they really wanted to, but it's a silly effect and servers no real purpose, so they don't. It's a bit of bling that makes my desktop look futuristic when I drag terminal windows around.

However I do notice that in Unity 8, windows stick perfectly to the cursor when they are being moved.

yep and i'm running this on an old celeron and i'm using mirscreencast and then pipe to ffmpeg to record the video. so what you see is unity8 running on old hardware and with cpu load at 100% :D

The cube is too distracting for most people to be involved in regular daily work, but more subtle 3D desktop effects really do make the experience more pleasant and are an important part of a modern, functional desktop environment. The "Expose" functionality popularized by OS X is one example of one such widely used and fully incorporated effect. Others include smooth animations on minimization, smooth flyouts (e.g., Windows 10 Start Menu), transparency, and tiling effects.

I really like the subtle 3D UI effects.. and the expose changer for OSX is really great with the touchpad.

Unity 7 works on X11 and Unity 8 is the new version to work on the new desktop server. I think it is on purpose to be as similar as possible.