I'm using the Cryorig C7 on my i5-4440 in my HTPC (Cooler Master Elite 110). When using the stock cooler, my full-load CPU temperatures were 72C. With the C7, my full-load temperatures were down to 58C. Both of these tests were performed with my room temperature being 20C. I didn't get the 25% temperature performance Cryorig advertises, but I'm still pleased with the 20% I got.
Most of the reviews I looked at before purchasing this were on YouTube. I really wanted to get Noctua NH-L9i or better yet, the Noctua NH-L9x65, but it came down to price in the end. The C7 was about 3/4 the cost of the NH-L9i.