Personally, I like clean, minimal designs. I'd have been happy with anything between 2-4. Stage 12 (or finished) is completely over-the-top for my taste. Tags are hard to read (red is too dark) and don't tell me anything about the depth or breadth of discussions that will be on these topics. Devdays font is coming off too strong in the final one. In Stage 4, StackOverflow was clearly visible and Devdays seemed pretty significant too. I was instantly able to make out that it was a 5-city dev conference by the folks from StackOverflow. In Stage 4, he could have highlighted some of the key words from the description to give more value to specific 'tags' and put simple links for buy-ticket, speakers etc. As it stands, it's very high on graphics, definitely very impactful, but not too clean or simple. However, that being said, it is still a very good design.