Hi everyone-I bought my Canon Xsi 3 years ago as my first SLR and have learned a ton with it since then. I have added several lenses as I learned what I shot most and what I needed in a lens. I now have a 50mm 1.8, a 85mm 1.8, the kit lens 18-55mm and the 55-250mm IS. I shoot a lot of sports, mainly basketball and soccer, but also general photography. I find I am frequently limited by low light and reach in gyms or on soccer fields. I am unsure whether it would be better for me to upgrade the body to a 7D for the increased ISO capability or buy a 70-200mm 2.8. I know it's usually better to invest in the glass, but given what I have, what do you think?