When I received this lens I expected it to be very heavy. I was surprised! It's heavy, but not nearly as heavy as my Panasonic 14-140mm lens. You might think that the fact that it's longer than the 14-140mm lens would be impractical, but that's not for me. But I scaled down a Canon 50D with a L 100-400mm lens and this setup weighed over 6lbs so 2lbs of this setup is a lot lighter anyway. The quality of the 100-300mm lens is good. It's not spectacular, but still very good. It's 600mm while my Canon L lens was 640mm. When comparing the same shots taken with a full telephoto lens, there isn't much of a difference and, surprisingly, the quality of the shots is very similar. This lens costs $529 while the Canon L lens costs $1500! I am very happy with the results from this lens and all Panasonic/Leica lenses I have purchased. The quality of the shots is not as good as the Canon EOS series, but close and less than half the price and 1/3 lighter, I'm very satisfied again. I now have a G2, 14-140mm, 100-300mm, 45mm Leica macro and 20mm f1.7. All those lenses and a camera with spare batteries, memory cards, charger and other gear in my camera bag weigh just over 7 pounds. My Canon rig with fewer lenses weighed 12 pounds. My Canon setup cost me over $5,000. My current setup costs just over $2,500. Half the weight and half the price. I'm sold for Micro Four-Thirds!