So, this certainly isn't an L lens, however given the pricepoint and image quality, you can't go wrong.  I've used this lens at a number of motorsports events where the image stabilization is a must have.  Before using this lens, images were blurry and just as many were bad as good.  With the IS turned on, things look great.  Additionally, being able to shoot in lower light has allowed me to take some shots that might have otherwise gotten away.  I'd buy again, though this time I'd add the lens hood to it. 

Question: What is the difference in image?
Answer: just as many were bad as good