Most (if not all) of you will say you prefered the one on the right. It's easier to read and more appealing. Why is that, you ask. Because the one on the right has:
White space helps make the poster orderly and inviting.
You don't put up much text in a poster because people don't have time/desire to read it.
The font needs to be large enough for people to comfortably read a few feet from the poster.
Short paragraphs make the information bite sized.