« on: February 03, 2014, 01:23:42 AM »
I chose the Canon but somewhat regret not getting the Tamron instead. I believe the Canon does produces better images, and from what I have seen from 95% of comparisons, it does.
However, IQ aside, my biggest gripe with the Canon is the quality control for this particular lens. I am on my fourth copy and it's still far from perfect. My first copy had a decentered element; my second copy clicked while zooming; my third copy clicked and I wasn't happy with its image quality; and now my fourth copy has a slight clicking sound as well.
I have given up trying to get one without any flaws because I don't believe they exist.
Another issue I have with Canon is their increasingly poor customer service. I spoke with a lady on the phone from Canon Canada after I sent my first copy of the 24-70 in for repair because of the decentered element and had it returned completely the same, and she basically told me I was wasting her time and Canon's technicians' time, claiming that I could never possibly test a lens as accurately as their technicians could.
My experience told me that Canon's customer service cannot be trusted. Now, to the misfortune of my local camera store, I now thoroughly test any lens immediately after purchase to make sure its within spec and I am 100% satisfied; if I am not happy it simply goes back and I get them to give me another copy, and I repeat this until I am happy. I feel dirty doing this because its not the store's fault that I'm obliterating their inventory, but it's really my only recourse to protect myself when dealing with a company like Canon now.
Tamron offers a substantially better warranty, is half the cost, and has a much faster turn-around time for repairs. I know Tamron has had their on quality control issues with their 24-70, but I really wonder if I would really have had to go through four different copies of their lens to be happy.