Ever since I switched from Canon DSLR to Fuji mirrorless, I have been unsure about what to do with my Canon gear. I invested so much in this brand, but the 5D Mark II was just not working anymore for my purposes, especially in low light and long exposure projects. I decided to order the auto focus mount adaptor from K&F and honestly did not have high expectations. These adaptors often don't fit precisely and are sometimes very hard to remove or install.
Well, today I took ALL of my Canon lenses out for a trip to test them with the adaptor on my Fuji X-t5. I am very impressed.
I used a wide angle, a medium wide-angle to medium close-up and the reason for buying the adaptor: my 200mm with 2x extender. The attached picture is taken out of hand at 400mm (200 with 2x extender) and it did a great job. It does even better on a tripod at this focal length but this bird was the true test, as it was not something I could prepare for. Had I come in with a tripod, it would have left. Now, all I did was lean against a tree for some basic support and this is what I got. This is a cropped and regularly sharpened image.
The miracle of this adaptor, that feel sturdy and has a smooth fit to the camera, is that it play really well with the Fuji body. I have full control over aperture and speed, I can use exposure correction and achieving focus was certainly acceptable. There were some situations where there was less contrast and it took a bit longer. But that is totally acceptable.
So, this is a good value for your buck - not just because it works as advertised, but mainly because it saves you a ton of dollars because there is no need to invest in a Fuji lens. My Canon gear now has retrieved its original value and more, because the Fuji body is such a top notch camera for my purposes.

This review is written right after buying the product. So if I find out that in time it operates less well, I will come back with a new review. For now I am very happy!