The 70-200mm f/2.8 lens is THE workhorse for portrait and wedding photographers. If you don’t own one and are thinking about purchasing, finding objective information about the different makes (Canon, Tamron and Sigma) is nearly impossible. I have read countless reviews, spoken with pro photographers and most of them become a little crazy when giving their opinion. That said, if you are a pro, make your living with photography, particularly if you’re shooting weddings, professional sports, the Canon is the way to go, without a doubt. The lens is built like Fort Knox. But, if you’re wanted to save nearly $1500 the Tamron and Sigma and viable options.
I finally found a review that is not a knee-jerk reactionary tirade. Check it out for yourself.