Yeah, reminds me of the CPU clock speed wars. [0] Shouldn't crypto security margin be $-oriented [1] related to the secrets / lives / etc. being protected? In backup / availability formally use something called a BIA to justify investments based on risk to operations. (A document used by IT people &| consultants to get business people to spend $ on backing up critical shit) [2]
Refs:
[0] http://c2.com/cgi/wiki?PrematureOptimization
[1] https://www.tarsnap.com/scrypt/scrypt.pdf p. 14
[2] http://www.ready.gov/business-impact-analysis