What sort of benefits have you seen from something like this in real software? I tried some techniques like this before, but in the end they didn't have much of an impact.

I've gotten mean server response times to go down by ~30% in the most extreme case, but the improvement was usually in the ~10-15% range. The real benefits came from shrinking tails that came about when some useless cache junk got rid of ALL the important data.

My use case was also preventing garbage processes from thrashing the cache, so the process using nontemporal stores was not the important process. A proof-of-concept merging of the two showed the same benefits from nontemporal stores, and the same principle applies anyways.