I quite like the robot mode for this guy.

it's an interesting discussion about the realism of alt modes for the films. I too have really enjoyed the "realism" and detail of vehicle alt modes for these movies. I've been frustrated by the non-earthen alt modes where they have appeared but they have always appeared on characters who either haven't yet taken earth form or appear to me to be too arrogant to bother taking an earth form. I found it very interesting that the war weary and tragically damaged megatron did take an earth form for the third movie as he was less self assured and more vunerable than he had been at any prior point in the films.

While "logical" the movie shockwave probably didn't feel a need to take an alt form as by the time he was spending much time in anyones view the decepticons had already started their invasion. Why then would he bother to conceal himself.