After playing in the Wifi Battle Tower, especially in the Rank 3 4 5, the pokemon teams with Jap names commonly use berries. For myself i adopted using berries alot more than just the Lifeorb/Choiceband/spec/scarf and Pure killing.
yache berries saves my garchomp alot
Occa( The Ground one) are especially good for metagross/magnezone
Wacan for Gyarados.
Grass one for swampert only if it can kill the pokemon aka avalanche a Grasser
The berries usually allow enough hp left so a Quick attack, Ice shard, Vwave or w/e wont be able to kill it. I usually see Garchomp near the red/yellow borderline ish after a stab Icebeam. and StabEQ on Metagross does 1/4, unstab does 1/5 HP and allowing it to survive another EQ, with like 10 hp lol
For me, its good for those pokemon who are still fast enough after a DD/SD/Nasty plot and then sweep.
Not sure the potential of using berries in 2 vs 2 or Trick ROom team.
Seen too many people looking for pure power/Pwnage or leftovers here and there.