Just spun up my ridiculously heavy rails app and did a quick test with one of the more cpu-intensive actions and see no evidence of any improvement at all. If anything, it was a bit less predictable.
This little test was nowhere near an actual benchmark, but I wouldn't hold my breath.
Test suite still passes on it though, so upgrading shouldn't be a huge deal at least へ‿(ツ)‿ㄏ
Test suite still passes on it though, so upgrading shouldn't be a huge deal at least へ‿(ツ)‿ㄏ