Vex In The Zone Robot Ideas

I am thinking of ideas for a robot. I was wondering what are some good building ideas. Also what is better a double reverse bar or a chain bar?

There are many threads on this subject. Please do a google search before you ask the same questions.

(Edited to add more links)

Our team is using a double reverse 4 bar is seems to be faster and more efficient but it really depends on your teams preference.