I have been playing the 12 post version for a while now and after a lot of matches paper/MODO I really think cavern of souls should be in the deck, it really helps against the delver mu. Here is the list I have been currently playing:

http://www.mtggoldfish.com/deck/233462

I have also streamed a few Legacy Daily events on weeknights, I don't currently own cavern of souls online but I should have them for the next stream and it would be really cool to have a few MUD players watching next time.