I've owned the two Sigma big zooms, the 150-500mm and the 150-600mm C, the Tamron 150-600mm G2, and the Nikon 250-500mm, all on full-frame Nikon bodies, most recently the G2 on my Z7. I used all of them in various settings, but mostly for birds and wildlife, although also for landscape occasionally. They were all good, but I was never completely satisfied with any of them—none of them delivered consistently sharp images, even on my Z7. So I was about to buy the Sigma 150-600mm S when I started reading many glowing reviews for the 60-600mm, so I bought it. Now I do blame the camera bodies for some the disappointment; the Tamron G2 on the Z7 just couldn't keep up with the action, which is why I bought a D500, the first APS-C camera I've owned in a long time. And I am blown away by the quality of the combination. The Sigma grabs focus instantly and the D500 holds on to it. My rate of keepers, and I'm very particular about what's a keeper and what isn't, has gone way up!

Most of the shooting I do is at the long end at 600mm which is the equivalent of 900mm on the D500, sometimes hand-held, more often on a tripod. However, I have found that it performs quite admirably at 60mm as well and I have no hesitation using it for landscapes and seascapes, on or off the tripod. I've tried it with focus-shift shooting at the shorter end and it is simply amazing. 

It's a little heavy for hand-held shooting (I'm 74), but I put a strap on it and carry it supporting it with one hand while walking and that makes it a bit easier to carry. I've hand-held it for fairly long periods, a couple hours at a time, and it is manageable, but that's stretching it. The attached photos were hand-held.

Sent back to Sigma and got it back within a week. They replaced the zoom mechanism under warranty. Have used the lens all summer on several jobs, and all is well. It's heavy, but still preferable for me over my Canon 100-400 Mk II zoom, which keeps losing its lens hood every time I have taken it out. This is still my must-carry lens, along with the Canon 24-70 to cover the whole focal range.

Wanted this to be able to get closer without getting closer. I am happy! This has good auto focus & the stabilization helps a ton. The range from the 60-600 has me only carrying 3 lens regularly, this one, a Sigma 24-70, & an old 17mm fisheye. Just be warned this is heavy but worth the weight. B&H was Fast wuth delivery too.

I have been doing sports photography for over 10 years now. I love this lens. Having the ability to zoom all the way to the other side of the field to catch a play like you were standing next to the player is great. Being able to pull back and still get a different player 10 feet away is amazing.

This is an incredible lens. It is my new favorite super telephoto.

nice zoom range, fast AF, usable f/stop range. Really nice lens for the price

It's a lens that stays in focus as the magnification is changed. Some might be close but close might ruin a video shoot.
NO! The new 150-600mm Sport is not PARFOCAL it's only $1499.
Coveted. TIPA https://www.tipa.com/en-en/awards/sigma-60-600mm-f4-5-6-3-dg-os-hsm-sports
and an EISA award. https://www.nexttv.com/post-type-the-wire/sigma-eisa-2019

I get the extra reach w/o the lag on an extender on my 100-400 L II with R7, and, BONUS, my 1.4 III works on it if I really need to reach that far

Cons: Heavy
Pros: Built like a tank. Photo quality excellent, although I have used it only in telephoto mode. Some reviewers have claimed it's soft at 600mm, but I have not found that to be the case. I did check mine for focus shift at wide and telephoto settings, and found it was absolutely spot-on in AF mode. Love the zoom locking feature. Have used lens at wide-open f/stop and at F/11, F16. Cannot detect any meaningful differences in sharpness, at least in the center of the frame. Will admit that for a long hike I might still prefer my much lighter Canon 100-400, but if I'm going for wildlife shots, by the time I put my 1.4 extender on the Canon, I'm still short of 600mm, and have lost any advantage in f/stop performance. MAYBE the Canon lens is a tiny bit sharper, but I cannot attest to that with any certainty. Since I bought this Sigma, it's all I've had on my camera, and I suspect it's going be be the #1 choice for 90% of my outdoor shooting. It's really a bargain at B&H's price!

Works well with my canon 80d
I had a contemporary lens 150-600mm
The upgrade gives me greater range 60-600 mm
It does communicate with my extender