I finally ordered my Canon XSI from B&H Photo yesterday. I was going to get the camera, 100mm Canon macro lens, and a tripod. The only reason I didn't order everything online is because I wanted to get a recommendation on the tripod. I ended up getting a recommendation on the macro lens, and the salesperson guaranteed me that I would be happier with the Sigma 50mm macro than I would be with the Canon 100mm macro. I ended up taking his advice and now I'm having buyers remorse because everywhere I read, it seemed like the Canon 100mm was the obvious choice. My question is, should I wait to get the Sigma in and try it out (I have 2 weeks to return it), or should I change my order? I'm new to the SLR world, so I don't really know the big difference between the 2. Any advice or experience with either or both?