Since I started experimenting with mos2 I haven't found an oil it doesn't mix well with. Subjectively they seem to run more smoothly and quietly, and there are tales of moly'd oils leaking oil through a cracked sump and the moly allowed some 'drive home ability'.
Objectively I never tested it.
In theory you should see lower wear metals in a UOA, slightly more mpg, and a little less NVH. Beware of using it if you burn oil, fouled up plugs an plugged up cats..