"Ideal" Grinding Spots

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?

Tiny Arm island is fine if you have a designted puller that won't go overboard. Pulling more than one Sanuwa with tiny arms can significantly slow down the kill rate (and NM spawns) due to all the dps being flung around, interrupting combos, missing positionals (since Sanuwas have a nasty habit of turning around for spite) as well as tiny arm's roaring damage down debuff.

Triceritops is much safer and more reliable provided you also have a designated puller. I've personally had better mileage with tricertops in regards to overall NM spawns (relative to party anyway, we had 6 spawns with three parties in triceritops, versus 9 spawns with 5 parties on tiny arms

Caves were pretty dominant day 1. The advantage clearly is once people are in the zerg, they're in. The coordination like "go <pos> now, noooooo dont fly off i bring mobs, yes fly off to pull some here" etc isnt needed. It all happens by itself. Its the easiest, both for natural inhabitants and coordination. Track Popped enemies can be a pain.

Dino took over next day because of high rank mobs that actually have no annoying skills either. It offers lots of mobs to pull, and space to move around. Way better for celphies, bisons and longneck, too.

Bird islands In HM. people often wanna go a bit slower and safer than these pull pull pull farms. They kill pteranods on small islands, seeing those are chilled 5s just like dinos are easy 4s. Problem is u run out fast, and then they go over to celphie island. Celphie is annoying. Also, fighting the S in small spots, see caves.

Personally ive never seen other "real farms". When you can choose between mobtypes
A) attack tank and aoe a lot
B) randomly hit people without agro, at a decent pace
C) inflict lots of status ailments...

The eastern island high above Dino Island is pretty good, the one with monkeys, birds and crawlers. We farmed there with 2-3 parties the other day after Dino Island got swamped with too many people. We spawned multiple Star ranks without trouble. I wouldn't say it's worth doing with a solo party though. You really need two full parties to make it worthwhile. The short journey between Dino Island and this location is beneficial should you be doing this for a short ten minutes in the hope that one of the many parties will time out of Diadem so you can head back to Dino Island and have a better chance of credit later on (essentially wait for them to shout for tracks and then go from there).

Added bonus of all the mobs on this island being easy kills with no horrible and annoying status effects.