70-200mm f/2.8L IS III USM vs original

[CapeCodDan]

I have a 13-year-old 70-200mm f/2.8L.  What differences will I notice with the present (III) iteration of this lens?  

[p4pictures · Accepted solution]

"Definitely, I would go for the f2.8 IS version then."

f/2.8 is helpful for a couple of reasons. Most Canon DSLR cameras automatically switch some or all the AF points to a higher precision mode when using f/2.8 or faster lenses. Also more of the AF points are working as cross-type AF points with f/2.8 lenses.