I currently run to music (150 bpm is my slow pace, 160 bpm the faster) as it helps me to pace myself. However, I should probably start trying to run without music. I'm sure many of you have made the transition: did you find that you went off too fast or too slow, or was it okay? I'm a bit nervous that I'll not do as well without the distraction / pacing that music provides!
(By the way, XTC's Making Plans for Nigel is a great slow-paced running song.)