Just heard this band's album "Dead Cities, Red Sea" for the first time. Wow! It totally blew me away! There are a lot of other bands, I think, that tried to pull off this sound, but ended up coming off boring or pretentious. But where they failed, M83 has suceeded. The songs have such a great movement and flow to them, while simulateously being very texturally interesting, as well. The range of volume on this album is what amazed me most. Ranging from a mellow introspective tone all the way up to engulfing crescendos that threaten to overwhelm you sonically, the songs are so dynamic. They don't neglect their percussion, either... there are some nice, chuncky base sounds here, as well as the subtle clicks and crunches you would expect.
The last word: It's extremely involving to listen to, and I'll probably pick it up when I see it in a store somewhere ^_^. My favorites were "Birds", "Run Into Flowers", and "Cyborg"