Aye, I can appreciate where you're coming from Mike, it does detract from the sensory experience of running somewhat and safety is a concern. It's the Nike+ motivation thing that swings it for me. Q quick touch of the screen tells me how far I've gone, at what speed etc. Before I had that, I didn't run to music at all. If I was in a club, or a Fun Run I wouldn't dream of using it. Antisocial like you say.
As it's our lass' iPod touch I have to use to get the Nike+ thing working I have little music that is to my taste on it too (although Living For The City by Stevie came on last night and that turned out to be a great tune to run to). I need to get a decent running playlist with tunes on it that will negate effect of the rhythm and speed changes that you mention. Mind you, I'm not out long enough to get through many tracks anyhow