The Plaid has 3 new motors designed to produce a flat HP curve, while the "new" 3 has the same old stuff warmed-over just a touch. The fundamental power curve is still going to be the same. A "Ludicrous" upgrade, if there ever is such a thing, will simply make it quicker to 50/60/70 before falling off hard.The plaid did. (well, nearer .3 but close enough).
But what you wrote seemed to be speaking authoritatively about it falling on its face, and now it sounds like you're just guessing.