plot-paris
There's not just one "correct" workflow when working with this aplications, anyone can do the same things using diferent methods, and because the main tools are about the same if you master one of the apps you can probabaly do just about the same things in the other two (as soon as you know where every tool is). And that's not the only way to put a cube in top of other. You can move the entire cube and align it using the axes putting the units, snaping to other primitive (i supose the cube is one of the primitives), and so on. Moving each face of the cube can't be the only way (imagine you're moving the mesh of dragon with 30.000 faces...you won't move face by face). But you can see what i mean.
The main diference between sketchup and the major 3D apps it's sketchup just working with faces and the others working with solids, nurbs and also faces. Other bigger diference, that for me is one of the things that is killing sketchup right now as a tool for 3D creatives, is beeing at the same time a presentation and modeling aplication. There's no render in sketchup, there's a optimized output, you present the model in the same space you use for modeling, "what you see is what you get" so the engine can't be fully optimized to just modeling or just rendering/output. In the other apps modeling and rendering it's completly diferent parts, what you see in the "model space" isn't what you're gonna get with the render.
So sketchup and Maya/3DS Max/XSI can't really be compared, and don't worry about beeing faster doing in sketchup simple things because that's an illusion if you're comparing a master in sketchup with a master in 3DS Max (or any of the others), and a master in 3DS probably means that he also masters photoshop (because he also makes is own textures, bumps, spectacular maps and so on...) so his final presentation will always be better than the one from sketchup...These software can also be very specifics, there's firms that have people specialized just in modeling, other people just for texturing, animation, or rendering. There's even a animation with maya class in England (for example) of 3 years with a one class just for texturing that takes 6 months...
The thing you have to ask is "Are you willing to have the patient, time, and dedication this kind of software needs to master it?"
David