I have never used an iPhone, so I apologise if this is incorrect but I've heard multiple times that the iPhone cannot multi-task at all. Indeed, if you want to play music you must do that and only that, you can't have it playing in the background (Spotify app has this behaviour for instance).

Even if Symbian isn't as pretty, it's so much more functional with any post N95 device you have enough memory and demand-paging to allow you to run a good number of applications simultaneously.