is the lens worth the $1500?

Good
> Pictures came at sharp at the F stops I shot at. I only really shot between wide open down to around F7.1 (as I was shooting F1 cars and needed high shutter speeds)
> Focusing was fast and silent as expected
> Build quality was excellent

Bad
> Solid build = heavy. This thing is heavy. I own an 70-200 F4L IS and that thing is fine but this you can really feel. Started to bug me half way through the day carrying it around in my bag
> Zoom push pull - I could never get the tight/loose setting just right. It was obviously better loose for quick zoom changes but then it would open itself all the time. If you put it too tight the zoom moves in large jerk movements.
> Dust - There was dust inside it when I got it but it didn't show up on my shots
> Slow - Even with a bright day and using it wide open I still had to pump up the ISO to get some of the shutter speeds I wanted.

I would recommend renting one to give one a go.

By the way it's $1360 at Amazon now with free shipping

If you need a zoom with some reach, and you're shooting in broad daylight, it's great. As mentioned, quick zooms while trying to nail a shot destabilize the lens. I find a twist zoom allows me to keep the lens/camera more stable. But that's a quibble. You can always pre-zoom to the focal length you need, then track your subject and shoot. Image quality is great if you stop it down to 7.1 or higher. At faster f stops, you'll lose a little sharpness but I'm talking about glaring at 100% crops.

well,
I am looking to do mostly outdoor photography, where I need decent reach. I also like the versatility offered by a zoom. Also, it was mentioned earlier about the push-pull zoom being a flaw, but I seem to like it over the conventional twist zooms I shoot with. I do not like the dust sucked into the lens through this feature though.
Anyways, I am looking for a fast autofocus in a lens with some sort of stability feature, IS in this case, and that will take sharp, quality photos at a decent reach.
Thanks for your reply.

thanks for your input.

Where did you end up renting it from? I had never considered renting a lens, had no idea where to do it, but I did a little research and found some places where I can accomplish this for around $70/week shipped. Anything I need to worry about with renting a lens.

the push-pull design is no more a "dust pump" than a twist design. Lens groups move the same amount whether the mechanism is push-pull or twist.

in speed and IQ.

I've rented it a couple times and enjoyed it. Obviously, if you can pick up a good copy used, you'll save some $.

A couple samples

<img src="http://panekfamily.smugmug.com/photos/188736747_pDxC3-M.jpg">

<img src="http://panekfamily.smugmug.com/photos/188736251_ABjAL-M.jpg">

<img src="http://panekfamily.smugmug.com/photos/188736724_EWckJ-M.jpg">

At this point, you'll need a reservation, probably a month out since it's a very popular lens in the summer. Nothing to worry about in my experience with lensrentals.com.

I think with a push-pull, the speed at which the elements move can be faster than the twist-style zooms, thus the impression that dust is more of an "issue" with the 100-400L. I've had dust appear regardless of why kind of zoom lens I had.

As others mentioned, if you can find a good used one, go for it. The price of a used one is very attractive, especially from the stuff I've seen here in Toronto compared to the new price.

I use the 70-200 is usm 2.8 L series all the time its my main lens for portraits i also use the 24-70 2.8 L series dont need that much reach for most of the portraits i do but would have some great boca<ul><li><a href="http://www.bhphotovideo.com/c/product/162616-USA/Canon_2577A002_100_400mm_f_4_5_5_6L_IS_USM.html">http://www.bhphotovideo.com/c/product/162616-USA/Canon_2577A002_100_400mm_f_4_5_5_6L_IS_USM.html</a</li></ul>