Quote (Eek @ Nov 9 2010 06:17pm)
The Non-IS and the IS version have completely different optics. The IS version is way way way sharper then the Non-IS version.
This is true.
The f/2.8 IS mk II is arguably the best zoom lens ever made. I would love to have one.
At half the price, the f/4 IS is also an exceptional lens.