A few strictly better additions, like Arms of Hadar, Winter Eladrin and Breath Weapon. Other additions just focus the cube a bit more. Notably, we tested adding the Gates to the cube. I initially worried this would make it too tempting to draft three colors, but it seems to be a fairly mundane change, no one ended up drafting three colors, so they should be fine.

Already looking to make the Double Masters changes, and it looks like they will be pretty explosive.