Yeah, Ive got to agree really... those weight figures really give you an easily visable comparison between the different materials, if you were to use a steel+x laminate, then the x might as well be polycarbonate, as it is very comparable in weight to the wood.

A solid panel of one material is obviosly stronger than most (if not all laminates) so I guess a wood+steel or polycarb+steel laminate would probably only be for teams on a very low budget from the start of the build.

We still havent gone over kelvar, or carbon fibre etc in much detail yet (I dont think), so that might be something to cover next, also softer plastics (which can be VERY cheap) like HDPE could be used for armour in many robots, I know that Dominic (http://www.ukrobotics.comwww.ukrobotics.com) uses HDPE in his heavyweight.