Anna Sullivan: I rented this gorgeous lens last Sept. while in Jackson Hole, Grand Teton & Yellowstone National Parks. I had fun with this lens and it took very good care of me. Even though I had no idea what I was doing, I captured amazing wildlife shots. I was very impressed not only with the lens but, how it arrived to me from borrowlenses. It had a padded backpack and a hood. Ready to go. This year, I'm upgrading to the 500mm lens since I know a wee bit more than I did last year.

SilverandBlueSports.com: This glass is amazing!!!! Add it to my D3S and your lugging an engine block around. I shot this lens hand-held during the Oregon Duck/Nevada Wolf Pack game last weekend. No monopod needed! The VR system on this lens more than compensated (the weight also helped to steady). The focus is ultra fast and always,always ultra sharp

Helena: I took this lens (and the 18-200mm) on a 10-day safari in east Africa and absolutely LOVED it. I'm a total amateur and I was thrilled to get some professional-looking shots. Yes it's big and heavy but if you use a good sturdy backpack (like the Lowepro Pro Runner 450 AW) with a waist strap, it's not so bad to carry it around (I wouldn't go on a long hike with it, but on and off the planes were fine). It's absolutely worth it.

David: Took this lens on an safari in South Africa. It performed exceptionally well. The zoom as opposed to say a fixed 300mm or 400mm was just what the doctor ordered for the South African safari where the animals can sometimes be quite close. I used the lens wide open at F4 or sometimes 5.6 in the dawn/dusk light @ ISO's typically in the 800-1100 range and had shutter speeds in the 1/60 to 1/125 range...any blur I encountered was only due to subject movement. I even have some panning shots @ 1/6 second where parts of the animal are sharp, and some blurred of course, which made a dramatic effect. I feel the best way to use this lens for action shooting is on a sturdy monopod.

Craig: I've rented this lens twice now from BorrowLenses, once for a 3 week African safari and once for a trip into Kermode Bear territory in British Columbia, Canada. The lens performed spectacularly for me in both situations, but there are a few things to be aware of. This is a heavy lens. This should come as no surprise given the maximum focal length and aperture, but it does bear repeating. For both of the trips I have used it on I had limited ability to mount it on a tripod and did a lot of hand-hold/bean bag shooting. I definitely, strongly recommend having a good bean bag for window/roof line use with this lens. The lens acquires focus rapidly, and can track moving animals in dim light well. One very important aspect of it's performance, though, is a tendency to lose sharpness at 50 ft+ to infinity, wide open. This is particularly apparent at 400mm. It is not BAD at infinity, but it is definitely not as sharp at this distance as it is at, say, 25-40 feet. Used in a situation where you are close to your subject (as tends to be the case a lot of the time on safaris, or when shooting bears from a zodiac or hide), this lens is simply stellar, while being a little easier to handle than the 500 and 600 mm lenses arrayed around you.