It is near time that I am going to get my Cannon 28-70 F2.8 but I just found out that they came out with a new Lens 17-55 F2.8 IS which One?I have 16-35F2.8.I bought these lenses for film Camera. Now this has changed with Digital.(Focal Length)The 28-70 has great reviews but the 17-55 has not been review yet.I am replacing my 28-135. Also Should I upgrade my 350RebelXT(350D) to 20D? Thanks for the Feedback Sean