Fast glass is nice but will cost more. Buying a T3i or even T2i to put more money towards the lens makes sense IMO unless you want some of the newer features. I can't say anything about the IQ of the tamron, but I remember that the version with IS is less sharp. For a beginner I'm not sure if the fast aperture is a must, you might want to recommend a speedlight 430 and the 50 1.8 instead, and let your friend figure out what matters more to him. My first lens purchases after the kit lens were not faster lenses, but tele zoom and a better walk around lens (15-85). Starting with a kit lens, you can save some money for later once they found out what way they want to go