Sophisticated Words?

International KOTESOL, 2012

When writing our thoughts, observations, and important things should we use sophisticated words to match of who we are? or to boast  how far we have been digging those words? or use words that everybody can reach and understand our thoughts, our implications of something, and desire of flying our mind somewhere in the wilderness of knowing and asking.
If you ask me, I'd prefer words that everybody can simply understand. However, considering what aspect or level, seldom I use complex words. (not to consider my grammar because I still have a long way to go....)