So I am going on a trip to Spain tomorrow and have been debating whether or not to get the Canon L lens. I currently use a Sigma 18-200 3.5-6.3 as my walkaround but am wondering if I should replace it with the canon. Is it worth it?? Will my pictures turn out that much better compared to my Sigma lens? The Canon is about $1100 OTD at a local shop, and if my pictures will be noticably better I think I will do it. Any thoughts? Thanks.