Obviously music on a bike is very subjective to each individual rider. I have experienced great sound on a bike especially with my two Gold Wings...they may be "recliners" but they could beat the crap in speed of most bikes on the road when you consider their weight...but they were tourers specifically built for that function.
Myself...I do not like helmet speakers, yes they have great sound as well but since the sound is right at your ear...to me...they block too much outside sound that you may need to hear on occasion to warn you that your riding situation may have changed. But that is me personally...if it floats your boat...keep on riding...it's just not for me.
But because of the enviornment we ride in if I am going to have a good stereo on my bike then I want great sound not something tinny or that is hard to hear when I'm up cruising in the upper ranges of the speeds I ride in. Obviously since I am buying a Harley...those speeds will be substantially reduced compared to when I rode a Thunderbird or the Rocket...or my Gold Wings for that matter. But I want good exterior sound and the ability to turn it off when I do want to enjoy my trip in silence minus wind noise and the muted sound of my aftermarket HD pipes (I don't do loud obnoxious pipes).
And since I have taken two 2,600 + mile trips in the last 9 months I want my tunes available when needed and off when I desire.
Different strokes for different folks...but that's my two cents worth.
Dennis