What's great about this product? Unlike Shimano 11-speed cassettes for road use, you can separate most of the cogs on the SRAM cassettes, allowing much more thorough cleaning between maintenance intervals. Additionally, the gearing is a huge benefit for these cassettes (11-36T) over the Shimano equivalent (11-34T). The spacing in the lower cogs is only 1T apart, meaning that the cogs go 11-12-13... and then fan out near the cassette top. This gives great ratios for flats and descents, as well as gear options for climbing. Moreover, these cassettes are EXTREMELY durable - I have yet to break a tooth, and I ride these for 10,000 mi+ in all sorts of weather conditions - they show minimal wear (I do keep them clean between rides, and especially thorough on maintenance intervals). They are made of very resilient steel. Although, they can be a bit louder than the Shimano counterparts due to having many different separate cogs separated by spacers, versus a lot of them connected via a couple of spiders, it is much more practical, and you get used to it. Again, this design makes the cassette much easier to inspect and clean. I would never go back to the Shimano equivalents. I always buy these, and I have never had any issue with them. HIGHLY recommend them if you're on the fence. Shimano "GS" derailleurs will shift 11-36T just fine - Shimano just specifies the maximum limit to 34T as they do not make anything larger than 34T. I've used these fine in 11-36T configurations on Shimano GS/RX derailleurs - mechanical and Di2. FLAWLESS.
Limited use so far, but so far so good. Very slick. Really like not having to run cables/housings. Operation is so smooth. I was worried about the initial set-up, especially since I haven't used SRAM anything in several years, only Shimano, but once I got grasp of a few concepts, it wasn't that bad. Certainly expensive, but felt like I got a good deal from Westernbikeworks. At least good enough to take the plunge. Now I want Force AXS stuff for road/gravel. That's the risk of trying something like this...end up wanting more!
This is the lightest and quietest Freewheel cassette I have used. I own two of these. The first one has 14,000 miles on it and looks and performs like a new cassette, I bought a second one to go on a new set of wheels. It was significantly cheaper than the first one was. A much easier purchase. I use it with eTap, but I am told that it works quite well with Dura Ace or Ultegra.