I prefer an angle aluminum robot,
1) It looks cool
2) Its stronger than wood
3) Its fully customizable
4) Its easy to machine, (our entire robot frame was made with a miter saw and a drill)
5) Its more forgiving
6) Its relatively lightweight (the entire robot weighed in at 117, and that is with a lot of #35 chain.
After two regionals, the robot has no dents, scrapes, or any problems from collisions.
People that are able to pull off a wood chassis that is strong enough have my applause.
I would recommend that teams try and design a custom chassis, then build it out of angle aluminum if they do not have much machining capability.