The difference is mostly not relevant these days. Yes, restrict is important, but anyone who is optimizing numerical computing hard is probably already using it judiciously, and for them what is more important is what is familiar to them and makes them most productive.
Unfortunately I see rather few people doing serious optimizing knowledgeably at all in research computing. (I know how and where it's done well, of course.) That has global effects on productivity of users, though some of the biggest gains can come from more global optimization, like in the use of MPI.
