Shame it doesn't have the extra gubbins in the manual that Lego puts on its instructions for their high end stuff that comes from their fan channel site thingy, ie interviews with the designers, history of the object being built, etc.
I thought about it a lot at the time and worked out how to do it, but concluded I don't want one. It looks way too awkward, the shell on the back and the rest stacked on the ankles look terrible. It just feels to me that without the stand it'll end up constantly in a crumpled heap.
If I wanted a big Unicron, and I don't feel the compulsion to, I'd go Studio Cell. It's so much cleaner and looks to me like it would work well with the SS86 figures in front of it. Haslab Unicron is too big for that.
I may very well end up removing the shell. The robot mode looks great without it. And Ive always had the thought of replacing the rings with 3d printed ones with LEDs in so no need to choose which mode gets the rings.