Why it's good: (1) The time and location text is large, making this an easy design to scan. (2) The white background clearly segments these blocks of text and helps lighten the right side of the design. (3) The different colors on the presenters help keep the text box from becoming a non-descript blob.
Why it's good: (1) The text colors alternate in a way that makes sense – you could just read the red text (or vice a versa) and get the gist of what this poster is about. (2) The most important information (when and where) is located at the top, in black text (easier to read than red), and with decent spacing and differentiation in text size.