As of right now you can't download the second part of the mythic maps yet. I'm sure it will be made available sometime, though.

I like Citadel because it is good for BR battles and sniping. I'm a BR whore. I pretty much refuse to play without BR starts, which is why I like Big Team Battle so much. Oh, and the new ranked playlist, Throwback, is pretty damn fun. 1 flag, 2 flag, or oddball with all BR starts. Love it.

btw, check out my bungie page.