Just to add my newbie experience - I went out tonight dressed up with my brand new Blackburn Mars 3, Cateye, LD1000, and Cateye EL500. Granted, for the past few weeks I've been using nothing, not even one reflector (and riding VERY defensively and mostly on sidewalks). Tonight I didn't feel once that a car didn't know I was there. It was great. This was in city and suburban surroundings with moderate to low street lighting.