Awful Typography
I think the typeface feels 'elementary' and clunky. There is a lack of a strong sense of hierarchy within the type. In terms of color, you might say the type is very grey, with no contrast or variation. I might reconsider the positioning of the elements on the page. More specifically, the venue date/time, sponsor logos and contact information. You are filling every bit of space in that container, and it looks awkward.
Why three arrows? Is it because of three hours? If so, then what happens to the concept if it is changed from 3 bands 3 hours to elementary? Concept is King, and I don't see much that sets this poster apart from any other posters. If I saw it walking down the street, I probably would not stop to give it a second look.
That being said, consider the purpose of a poster. Who is the audience and where will they primarily be seeing it? Look at other posters/flyers/etc., what do the successful ones all share in common?
No appologies here for being harsh. I understand where you might be in your thought processes, however, I think you need to push everything farther, starting with a strong concept. You will find the farther you go that without a concept, a project is doomed to fall apart. Find it, exploit it and make it work for you.