With my kit I noticed the engine starts quicker than before, noticed a slight power increas as well.
i doubt this solely for the fact that it's hard to notice at the MAX 2 whp.
Doubt it all you want; I'm in tune enough with my vehicle to notice.
On cold mornings I can feel that slight increase in power vs a hot afternoon; that difference is but a few horses.
When the dealership put a GT Oil Filter
on my GTS by mistake my first tip off that something was wrong was the engine felt ever so slightly more sluggish, again this difference was likely only 1 or 2 hp. Its a matter of perception.
Hard, yes; impossible, no.