I bought my Nikon 70-200 used (as I buy most of my lenses) and I am very happy with it; I've never had a problem with a used lens, and I would always rather have a top-end name-brand lens bought used then a new third-party ('though I can't speak to specifics on the Canon lenses).
In fact, i wanna differences between both lenses. Considering Canon one an older model versus the tamron last version which is frequently compared to canon mark II. Whats your experience ou opinion about them, which model should I buy ? Thanks
I just purchased the Canon 70-200mm f/2.8 IS USM *used*, I can't wait for it to get here. I will post again when it's here. I was going to purchase the Tamron 70-200mm f/2.8, BUT changed my mind and went for the Canon L series. I've never used any third party lens other than my friend's Sigma the other day, for a few shots.