Very little cost to protect your carbon bike that cost in the thousands. I have these on all of my bikes and the gravel bike is no exception, prior to first ride this was installed and prevents chain drop and damage to your frame, it is a must buy.
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!
Jagwire's Pro Shift Kit is a handy package that has everything you'll need to re-cable your front and rear shifters/derailleurs (cables, housings, and hardware). The cables are lightweight, strong, and long-lasting, and the housings (available in a variety of colors) are pre-lubricated. The housing ends and ferrules are well-made, and the included instructions are easy to follow. The cables provide quick, crisp, and accurate shifts -- better and more durable than other cables I've used. Highly recommended -- you won't regret buying them.