But you have to factor in the amp used to make the impulse...IIRC, the Catharsis impulses were made with a 5150, so you ARE getting the power amp imprint in the impulse...The knob settings may be different than you'd prefer, but the power amp is still "there".
Except you're only getting some static EQ, there is no compression, saturation or any non-linearities at all in an static impulse. So I'd say the power amp isn't "there", just some slight EQ, definitely not the same as a real power section