i have the canon 24-105 L lens that came in a kit with my 5d. before i got the 5d i purchase the tamron and got amazing results on my 30 with it. when i found out that i was getting the 24-105 i returned the lens thinking it was goin to be much better. now that i have taken a few shots with the 24-105 im thinking that i would rather have the tamron. am i crazy? wait ... i know i am crazy but would you think its a bad idea to sell my 24-105 to get the tamron and some other equipment that is needed?