I'd agree that Canon L lenses are superb - after trying the odd sigma etc out I've decided that even the more expensive models just don't compare with Canons.
Canon has often been the preferred DSLR for professionals, probably due to the excellent autofocus sytem and the low noise levels. I'm impressed by the Nikon D700, but I've no plans to switch brands just yet
Totally agree about the Sigma lenses, a lot of right ups say they are soft at the top end, Ive found all the ones Ive tried were soft right through when compared with Nikon glass..but on saying that, most of the people at m