The Join button stands out with a nice contrasting blue. Like the use of great visual images, although they may look a little bit like stock images. If we have an image heavy website, we would like to take our own photos.
Dark infography - Music - Amazing how simple charts can become so complicated. The reason for all the bendiness, color categorizations and legends is to make it look cool. Most of the time, simple is better.
I like the fact that the main content on the page never disappears, although the interacting with the side bar is at an all time high. It& a very clean layout with flat ui colors that speaks nicely to the flow of the app.