I have just over 10.5 k miles on my '09 RK. Unfortunately for me, I have tinnitus so I can only wish I heard the whine. Honestly, I don't hear it. My hearing is impaired in one high frequency "zone" only somewhere under 20KHz I have a large drop, and then there is the constant ringing. I can't hear certain sirens/alarms like those used on computer servers to alert personnel that something is amiss (that part works out well), but as for the 5th gear whine, I can't tell the difference from other noises the bike emits. The wind makes more noise as best as I can tell, so I wouldn't worry about it too much.
jl