Upload & Sell: Off
While we're at it then, the Canon 17-40 F4 weighs 600g. It's not as fast but may be more versatile with 17mm on the short end. It's pretty cheap, too.
I wouldn't hesitate about getting this lens if it wasn't for the IQ on 5D2 that I'm not impressed with. While like Nikon 14-24 F2.8 is clearly a stellar optical performer, its weight and more importantly cost put it outside my capacities for travelling.
The Oly 21/2 beats the 17-40 in terms of sharpness in my experience. The 17-40s extreme corners never get particularly sharp but are acceptable at f8-f11. With that said, the 17-40L is still an incredible lens overall (colors, AF, contrast, build, weight, price).