We used 99designs to create a logo or our not-for-profit organization. Once our brief was submitted, we immediately started receiving high quality designs. If I could offer any advice, I would say the more detailed your brief, the more your "rate" designs and designers, the better your results will be.
Product : The designers were extremely easy to work with, and took guidance and feedback very well. We were very happy with the final logo and would certainly return to 99designs again for our future needs.