Canon 70-200mm IS USM Mark 1

Looking for some POTN user's advise. I currently own the Sigma 70-200mm OS HSM, but I have found some Canon 70-200mm IS USM Mark 1 for sale. In your opinion is the Canon any better than the Sigma, in terms of IQ? I am about to upgrade to the 7d mark ii also.

This link shows it is considerably much better.
http://www.the-digital-picture.com …omp=0&FLIComp=4​&APIComp=1

I'm also guessing the AF will more accurate and faster, as it its not reversed engineered.

I bought one used for about half the price of the Mk II and it's terrific. I'm sure the Mk II is a better lens, but the Mk I is plenty good enough for me and has never disappointed.

The 70-200 is mark 1 will be better than your sigma..I owned the mark 1 and it is a good lens you won't be disappointed..
I have just upgraded to the mark 2 and that is just amazing..

I concur...Mk1 is excellent...Mk2 is AMAZING!