This would be an insta-buy for me if it wasn't a 3 lb lens. Honestly, if Canon could simply match Sony's last two zooms (20-70 ƒ/4 and 24-70 ƒ/2.8 II) in size, weight, and IQ, I would be really happy. If those two lenses had existed when I switched back to Canon, I might be shooting Sony now...