At least DPS wise, Blizzard have taken out the damage coefficient for Imps because they were doing way too much DPS. So right now the only thing Imps are good for is the stamina buff!

The coefficient has been removed until we can get the proper spell damage fix into the game. When the coefficient was being applied incorrectly, utilizing talents created a dps output for the Imp which simply could not exist in the game without being a large and unintended advantage.

While the removal of the coefficient is somewhat extreme, it is a temporary measure. In a game state, it is no different than having your Imp on passive, so we are settling with that for now until we get the proper fix in.