Summary: The 70-300mm lens takes great pictures and with the IS on my E3 I can shoot low shutter speeds with very good results. It is a good lens for street photography or portraits. I wouldn't recommend it for sports due to it's slow focusing, which is worse in low light.
Pros: Great lens with more reach than the 40-150mm
Cons: Slow focusing. Sometimes I have to shut down my E3 and restart it to get the lens to respond well.