If you can find a Larvae, obviously that's the best way. It's a bit slow with the Mana Elemental's respawn time, but it's leagues ahead of killing 60 Makai.
That being said, 60 Makai is still much better than ~600...
Also, another item worth grinding for is Cavern Celestite, which normally has <30% drop rate. 1600 for the NSoD, and a multiple of 200 for a Receipt of Nulgath.
You can't get Receipt of Nulgath on the test server because you would need to travel to Nulgath, but you can still get lots and lots of rewards from the Gem of Nulgath pet, including the extremely rare Unidentified Gemstone. You need Drudgen, Crag, or ENNH to get the Uni 4 and 5, though.
Also, those quests that have a 100% drop of an item, and then have a "you may receive" of more of the same item, such as High Legion Champion's LTs, finally drop properly on the test server. This is especially relevant to LT farming, Gem of Nulgath pet, and anything else in that category.