You like to organize your island? Don't try it, you can't go back if it doesn't work out.
You like efficiency and new iBuildings? Don't try it, that new 2x2 building might not fit where the old 2x2 or 3x2 building was.
You like upgrading - yeah, you can still do that, but the buildings will cost more to move someday, so maybe don't do that either.
You like your island the way it is today? Great, you'll love the new update. Until Easter, when new iButchers come out.