If it is for a project, consider the following:
a) Brainstorming - gets you good marks for ideas that look good on paper but that you should realise are not feasable for safety/ practicality grounds
b) Projects have to be completed within a timeframe... make sure you can finish it
c) A heavyweight robot is expencive, difficult to move and extremely dangerous.
d) A featherweight robot is much cheeper, easy to move and can be built safely (and much quicker).
e) Antweights are even cheeper, can be put in a pocket and still incorporate some serious firepower and technology.