Cryorig's site lists the QF 140 performance version at 128 CFM (@38dBA, not exactly silent). Fwiw, I haven't seen any graphs for it yet, though I'll give them the benefit of the doubt its around what they claim it is 'til proven otherwise.
CFM Ratings on fans are absolutely useless, even more so than monitor response time. Fans like any pump (a fan is essentially an air pump) have flow characteristics whereby flow changes with back pressure. So a fan may deliver:
90 cfm at 0.0 SP and 0 cfm at 1.20 SP. I may actually operate at 50 cfm @ 0.70 SP. Unfortunately there is no standard on how these figures might be presented and the most common leaves the impression that the fan can deliver 90 cfm at 1.20 SP.
Good Reading here:
"Why Static Pressure & Max Flow Specs Are Poor Measures of Fan Performance"
In my experience, more than 1000RPM for case or CPU is rarely needed though.
You'd think why not just get the one with more performance and then THROTTLE it if needed right? Price aside, when booting the computer up the fans usually ramp to max for a few seconds which can get pretty annoying.