JUST BEEN IVANISED!

[AyJay]

According to some, the difference is immediately noticeable and claim "Night & Day" difference, but that's not the case with mine. I wonder if pre-2003 owners notice the low-end difference more?

That was the case with my 2001. The top end rush was improved as you've found, but it was the snap throttle response at any revs that was the revelation and the real 'night and day' difference. That comes from clipping the carb springs, I believe, so maybe yours hasn't had this done, or maybe they weren't clipped to the right length ie short enough. Certainly, snapping the throttle open at 2500 revs is enough to lift the front and that never happened prior to Ivanising, and it's much more responsive to the throttle than it was too.