I have had the Tamron 150-600 since it was released early this year. I sold the lens yesterday, because I just cannot live with it anymore.

I sold it for 40% less than I paid for it, and I'm so happy to be rid of it that I'm not bothered about losing such a big chunk of money.

Firstly there was an issue with it battling to find autofocus. This was resolved when I discovered that there is a 'secret' firmware upgrade that Tamron didn't feel it important enough to let their customers know about. 3 Weeks after shipping it off for upgrade it came back and was able to focus like a normal lens.

So, that fixed the autofocus issue, but no amount of workaround would solve the fact that it is just a soft lens at all focal points. (At least my copy was). A photo of the sharpest tack would make it look blunt. I joke that even a couple of Viagra wouldn't cure it's softness.

With a Canon lens it would have been easy to get the Canon service guys to sort it out, but with Tamron, every time I need it looked at, I had to ship it cross country and wait 3 weeks for it to get back to me. Eventually the aggravation factor got to me.

I'm sure the lens is repairable but I haven't got the patience and time to force Tamron to do it. Tamron products may be good, but their service is hopeless, and I'm not prepared to live with that..