I am using this lens on a 5D3. First the focusing is an issue since the camera is having problems it does not have with any of the other (5) L lenses I use. The ISO is also kicked into really high numbers in indoor shots and for no appreciable reason, resulting in very noisy shots.

iso quirkiness; Semi-sharp images

Great lens. Bought to cover all other lenses, in other words, we do not have to swap lenses now. It is a bit heavy, and needs to be rested on something to take good clear pictures. Ideally it would be better if it was lighter. Ideal for a male to use, but a bit heavy (unless you are a weightlifter!

"This L series lens is exactly what the travel photographer wants. Mostly. It's a perfect focal length range for a full frame camera body, it is very sharp and despite and extended focal length range does not exhibit significant barrel or pincushion distortion.

Canon's EF 28-300mm lens gives me a versatile, high quality, professional lens for my outdoor photography. Image quality is excellent and I couldn't resist the discounted price.

Versatility and image quality

Heavy; but the versatility is worth it

So far so good. I am enjoying the lens as a single travel lens. However the salesman did not tell me I was getting a grey market product. I do think that should be revealed before purchasing.

I bought this lens as a carry one lens/one camera while traveling and hiking. I like the zoom range and the picture quality obtainable with this lens. It is heavy and expensive but gets the job done without carrying a pack of prime lenses. This is one of the best zooms I have ever used.

I've had this lens for a year now and I use it nearly every weekend for taking pictures of youth soccer games. The lens focuses very quickly compared to my old Canon 70-300mm and the pictures come out very sharp.

Great lens. Nice lens to have if you don't want to change out lens during your trip. Love the fact that you only need carry a single lens and still have a wide focal range. Great optics, produces sharp pictures. The weight is the only downside to this lens, but well worth the workout.

Versatility; quaility; image stabilization

Weight; price

it is a versatile Lens , good if you travel , so you can cover a wide focal , instead of carrying different lenses. It is scary to people that you want to snap shot them. A little Heavy , but doesn't bother me at all. It feels like a Tank . and makes you proud.

Strong Construction; Consistent Output; Durable; Rugged; Fast / accurate auto-focus; Easily Interchangeable

Heavy and scary to people; Heavy; Lens Creep

it is a versatile Lens , good if you travel , so you can cover a wide focal , instead of carrying different lenses. It is scary to people that you want to snap shot them. A little Heavy , but doesn't bother me at all. It feels like a Tank . and makes you proud.

Consistent Output; Durable; Easily Interchangeable; Fast / accurate auto-focus; Rugged; Strong Construction

Heavy; Heavy and scary to people; Lens Creep