>>21507606>Good-Counters Rotom-Wash
-Checks non-Swift Swim Grass weak Waters
-Can switch into Twave/Volt-switch for free
-145 base Speed
That's it. It's typing is terrible, it can't get Draco Meteor, it has only Sword Dance for boosting a stat with no moves to abuse that's over 100 base power, and has not the power to go mixed, nor the power and coverage to go fully special. It's typing is trash, neutrality to Fire doesn't make being one-shot by Ice Shard worthwile (whereas mono-Grass would have been able to switch into something like HP Ice and live).
Dedicated fans will use its okay Leaf Storm (145 isn't too hot without an item boost) and good base Speed, but that's about it. Its base speed will let it be useful in NU/RU, wherever it ends up, due to the lack of Mega competition in the lower tiers.
If you wanted a good Grass type in Hoenn, go with Ludicolo, Roserade, or Breloom.