Now that Diadem has been out for a week, what have people determined to be the "ideal" grinding spots?

I have seen a couple in the general vicinity of Dino Island, one with Triceratops, Banemites, and the occasional Islekeeper, think it was (30,26).
And another which is accessible via a hole in the canopy near there, with a number of T-Rex mobs within a pull-able distance, not sure what the coordinate for that spot is.

What other particularly good spots have people found?
And would you say that certain ones are better for Hard vs Normal?