Pro: Great image quality, especially for available light portraits shot at f2.8 where you want a pleasingly blurred background. The IS is good but see note below.Con: Weight if you plan on carrying it around all day on a pro camera body.This is a great lens and if I didn't also own the 70-200mm f4.0L IS Canon lens I would have rated it 5 stars. IMHO the f4 is a better all around carry lens if you don't absolutely have to have the f2.8 aperture. The IS in the f4 is Canon's latest and is usable up to 4 stops slower shutter speed than you'd normally need at less than half the weight. The 2.8 version uses the very good, but older, 3 stop IS. On the surface you would think that the f2.8 aperture being one stop faster would place them on even ground where IS is concerned but it does not. the newer IS on the f4 version is INCREDIBLE in operation! To be fair to the 2.8 lens, given the same lighting conditions, it gives you one full shutter speed faster that may make a difference if stopping motion is needed in the shot. My best advice is to not end up with both lenses becuase it is so hard to decide which one to take along!

It works great, not having to hold the phone and activate shutter, with your other hand.

Not always easy to get the function light to activate. Fisheye lens is much better at a distance of more than 10 feet. Bumper case doesn't allow light to show.

At $70, this is a great piece of equipment. Far, far better than anything in this price range I've ever seen. Even with a very heavy Canon f/4.5-5.6 100-400mm L lens and a 5D MkIII, it was far more solid than tripods in the same price range you'd find at typical big box department stores. A lens this long, fully extended, is going to be a challenge for all but the most sturdy tripods - there was a tiny amount of vibration from the shutter release, even with mirror lock-up.**Disclaimer - I haven't ever worked with a high-end, sturdy, expensive tripod, so I don't have a comparison except to low-end models. But I can tell when my camera rig is solid.It's quick to setup and tear down, build quality feels excellent (aside from the plastic dust seal rings on the leg joints, which seem to slide out of their place easily). The ball head held the camera configuration above well, and the swiss/arca mountain compatible plate is a bonus.It also held my 5DMkIII with a 100mm macro very well, I could even trigger the shutter manually with no visible wobbling.I wasn't looking for "light weight" even though I'll do quite a bit of hiking with this strung to my back. The CF model is lighter, but I wanted stability. It feels very solid when holding it, adjusting it and moving it about.Though hesitant to order a low-price import, but I'm pleasantly surprised.

I have owned this lens since February 2005 and have used it exclusively with a Canon 20D. This is the second L-series lens I've bought from Canon (the other being the 24-70mm f/2.8L). Before buying, I researched the different versions of this lens Canon offers (IS, non-IS and non-IS f/4). I looked for every reason 'not' to spend the money on the IS version but ultimately got it anyway. I have never regretted the purchase.You should know that IS (Image Stabilization) is not a miracle cure for camera shake, but it does give you the equivalent of two or three stops in terms of usable shutter speeds. A motorized gyro inside the lens helps compensate for a modest amount of camera shake. It's powered by the camera's battery. That means if the slowest shutter speed you can shoot handheld without unacceptable blurring is 1/60, you will be able to shoot 1/40 or maybe 1/30 with IS. In some situations, that's the difference between a photo that's a keeper and one you toss. Of course, you can still take blurry photos with IS--as I said, it's not a miracle cure, but there's no question it's a worthwhile feature. This version of Canon's IS can be used with a tripod unlike the older version on some other Canon lenses such as the 100-400mm L, which cannot. It has two modes, one corrects for vertical motion only (for shots where you pan with a moving subject) and another that corrects for both horizontal and vertical motion. Note: IS does NOT compensate for subject motion--the only way to slow subject motion is with a faster shutter speed. IS is purely a feature that helps avoid the blurring caused by the camera moving.My copy of this lens is very sharp at all focal lengths. Color and contrast are excellent. I really don't have a single complaint about this lens. Some people find the weight objectionable, but it hasn't been an major issue for me. Unless you need to be physically running around to capture your images, or unless you have to hold the lens to your eye for lengthy periods (isn't that what tripods are for?), I don't see that it would be a problem for most average-sized, healthy adults. I often carry my 20D in a shoulder case with this lens, the 24-70mm L and a 580EX Speedlite. Hours of carrying this bag around does require transferring the load from shoulder to shoulder periodically, but it's a price I'm willing to pay to get quality photos.I own Canon's EF 1.4X II teleconverter and have used it on this lens with great results. The 70-200mm is so sharp to begin with that there's no appreciable loss in sharpness when combined with the 1.4X TC. Reportedly, the results from the 2X TC are not as good, and some find the falloff in sharpness to be too much (not just with this lens, but with any of the telephoto lenses).This lens is highly recommended. If you can get over the steep entry price, you'll have a high-quality optic built to last for years to come. Of course the non-IS versions can take beautiful photos as well, but having lived with IS now, I've been spoiled.Update 5-17-10: It's been 4 1/2 years since I wrote this review, and I continue to use and enjoy my 70-200mm, which is now paired with a Canon 7D. Anyone considering buying this lens today, however, should know that Canon updated this lens earlier this year. The mark II version has improved optics and the latest generation of IS, but it is priced $500 (MSRP) more than its predecessor. Check Amazon's listing for the mark II to see the exact difference in price.

This is an awesome lens.Obviously use a tri- or mono- pod at lower shutter speeds

Not super sturdy, but it really doesn't need to be. Bluetooth shutter/activate button sometimes works, sometimes doesn't.

excellent product of excellent quality has adapted to the product a product that has adapted to my body