Is the Canon 24-70mm f4 IS a good choice?

[IntrepidB]

I've recently upgraded from a 70D to a 7D Mark II and unfortunately my Sigma 17-50mm (very sharp, my best lens so far) isn't compatible with the new body. More details on: Sigma 17-50mm didn't like my new Canon 7D Mark II | Photography Forum

Sigma is taking a long time to reply my emails, and I just can't afford to wait, my work demands a versatile lens and I can't keep switching lens all the time.

Since I'm planning a future upgrade to a full frame, I'll avoid APS-C lenses like the 17-55mm, and it seems that a 24-70mm will be the choice (I know I will lose some wide angle range, but I already have the 10-22mm for those situations).

By the specifications and reviews, Tamron has the best 24-70mm out there. It's sharp, 2.8 and has IS. However, since my recent problem with that Sigma, I am not so excited about getting another third party lens. What if next year I upgrade to a 6D Mark II and the same thing happens again?

The Canon 2.8 is extremely expensive (and has no IS), so I'm left with the f4.

Is this 24-70mm f4 IS as sharp as my old Sigma 17-50mm? Is it durable and bulky? Are there any common issues I should be aware of?

 

[ygb]

I just broke my older sigma 18-50mm f2.8 and I was going to fix it, when I came across your post that it doesnt work with 7D mk ii. I just got my 7D mk ii last night and it was suppose to be my christmas present, but after seeing your post I got worry that my tamron 70-200 will not work with it, so I pulled it out and I didnt see any issues with the focus.
I think it's probably depends on what you shoot but when I shoot portraits I like to shoot shallow and considering that f2.8 on the APS-C sensor is not f2.8, but f4.5 where depth of field is concerned. I dont think I would like the lens that limits me to f4. I just rented canon's 24-70 f2.8 ii and loved it, so I put tamron 24-70 f 2.8 on my wish list.

Yuliya