Personally prefer to save spirits Platinum and Black spirits for better boosts than that, but isn't a terrible boost, true. I'll admit I was not aware just how high the drop rate for platinum spirits is on the X map, which while not 100% is quite close to it (especially with Cellia on the team). Usually, I prefer to run the G map for the higher black spirit drop rate and to a lesser degree, the higher Rainbow Spirit drop rate. Still, I might need to run the X map few times soon given my platinum units in need of leveling.