TL/DR Under the right conditions I am still getting ~170k exp per battle.
Details: I have been grinding Arcane Eyes the last few days to level up a raft of battle pets, and under the right conditions I am still getting ~170k exp per battle. I'm not sure what was nerfed, but someone might find this information useful.
My character is level 88 (86 when I started a few days ago). I had been only very casually grinding up battle pets -- my highest was a level 13
Sinister Squashling, and I had a variety of pets in the level 5 to 10 range. I followed some advice and took my Squashling, a level 5
Tiny Harvester and something else (I forget which), and went to capture an
Arcane Eye, which turned out to be fairly easy. They only fight solo, so even a low level team of three (of course avoiding using any low level Flying or Aquatic pets) can usually take one out.
I then started grinding up various pets in my collection; I would just rotate teams during the 8-minute heal timer. Each fight would get me about ~170k exp (varied based on the level of the Eye.) I quickly discovered that
Lil' Deathwing was an Arcane Eye wrecking machine; even at level 8 he could solo two or three Eyes in a row before needing a heal. He would get 220 pet exp per win up until he hit level 16, then the exp dropped to 207.
I tried other nearby zones. In short, I would get ~30k exp for winning a battle significantly below my team level (e.g. Northern STV) and ~170k for winning a battle at or above my team level (e.g. Blasted Lands). What made it more difficult, of course, was not being able to predict with certainty the composition of the other team.