I'm not surprised prop noise hasn't decreased much in 8 years - it's not a priority in most commercial builds and nor would most of us want it to be - stealth is not usually much of a factor in our flyings I would imagine, and making these things...
Bitrate i.e. amount of data per second is the same, there are more changes to track at 60fps but each of these changes is smaller so it should pretty much even out.