
Originally Posted by
nerfedname
They removed the spell effect that takes away "X% of 'REMAINING' hitpoints," so it does a flat 25% damage on all structures. Because of this, it doesn't matter whether you drop it early or late, if the TH has 5000 maximum HP you're going to do 1250 dmg (with a lvl4 quake). If the TH had less than 1250 hp at the time, it will go down.
The wiki is quoting for a lvl 1 quake.
In summary, upgrading earthquake DOES matter, but it's not a huge upgrade priority and I would save it for last. As far as taking them to a raid, yes, I think they can be useful and I do use them on occasion when GiBarching (if you're willing to spend the DE on them).