I'm playing Jaco Drazi because I want to have a deck for sanctioned play and Power is just not in the cards (hehe) for me right now ...
Also I do enjoy the deck. When it works, it's really fun to play. When it doesn't ... not so much. But that's like a lot of decks.
No spheres for me. The way it's setup it's not really a prison deck (unless falling into Null Rod/Crucible/Strip somehow). More of a very aggro deck with some disruption.
I've played it in a few tournaments and have sideboarded in the Newlamog several times but never cast it ... and I think the World Breaker has only worked once. But I like the feeling of having "an out" to almost anything ... but then again I might get rid of it.
The main reason for the ESG's was to be able to play out from under a Workshop's turn one sphere, which has worked several times. They will help with the World Breaker too though. For example Workshop player goes land, moxen, sphere or similar and I can go Ancient Tomb, discard ESG, Null Rod which can work out against Shops.
This thread has a tournament result with deck lists where I came in second with Unpowered Eldrazi:
I really enjoy playing the deck. And although a lot of the cards are "givens" it's fun to tweak it to my tastes and style and what I think will work well.
I wouldn't play any artifact with an activated ability so that the Null Rods are as one-sided as possible.
Since you have some time before the event I would really recommend Jason Jaco's book available from Eternal Central. I'm sort of a newb to Vintage and it really helped me get started with the deck.