I'm sure you've read one million of these posts, but I need some advice on lenses. I would really love a 400mm L series lens, but I havn't met that rich older woman yet so I've got it narrowed down to two. I am looking at the Canon 75-300mm f/4-5.6 and the Sigma 28-300 f/3.5-6.3 Compact Hyperzoom. I am really uncertain of the Sigma quality. I shoot with a 300D and want a longer lens now. There is about a $200 difference in price, but quality is my #1 concern. Ideally I'd like to see some samples wth both, but I don't know if I'd get that. I want to use this lens to shoot everything from wildlife to concerts to general photography and portraits. If quality is my #1 concern do I save up for an L series? Where does this cycle end? Should I even expose myself to this level of quality?...oh wait.....damn photo sharing 20d owners! 

