three cards I'm not sold on
Goblin Warrens: I dropped mana echoes, dropping mana echoes pretty much means this card becomes superfluous combo and win-more. It's one thing to border on infinite goblins as a back-up plan, and I still like it for that. But, probably out for now for Shivan Harvest.
Hoarding Dragon: just not sold on it. I'm too afraid it's going to be removed from the game to trust it with much unless I can kill it. I'm short on sac outlets. Not sure if it's better than Charmbreaker Devils, but I'm short on instant/sorceries too.
Starstorm: meh. Don't get me wrong, it's great, but by the time I have the mana to play this I can/could have done something else. I feel similar about Comet Storm (but don't intend to drop it) now that I'm not running mana echoes and half-shooting for near infinite mana.