I do not know anything about dial up, how fast it works, if subscription versus downloads are better. Sorry. One thing you may be able to do though is most places will give you a 30 day trial (I think). May want to take that and try it first, especially before signing up for any long term things.

BUT the reason I am replying - I do not believe the iAudio U2 supports subscription based music. I know it does not on Rhapsody

http://music.guide.real.com/rhapsodydevices?rnd=1141338663669&bw=411&has-player=false