I would say my Scythe is as quiet or has a slight edge to my gen2 ultra 7. Close sound wise. Recoil reduction goes to scythe. The new brake adapter is interesting for NRL match or something else and using ear pro. however, with all the posts about scythe failures, I'll probably just leave it on the 6.5 creed and use something else on 7prc and 300 prc. My magnus is much quieter than both, and more recoil reduction than ultra 7.
TBAC has an interesting graph on their website comparing the different cans sound and recoil reduction data, ultra 7 recoil reduction is quite low. Sound reduction for its size is pretty impressive. As others above have pointed out, volume and design matters. Some interesting developments with the 3d printed cans. interested to see how the UM OTB turns out as well. If you have time and can tolerate it pew science and the jay situation podcast have lots of info/data on several top performing cans. Just have to sift through and find the ones you're interested in