10+ years and no big accident (for small bumper accidents, ABS would not make differences anyway).
Without ABS I felt the braking distance is shorter (comparing with my other one, which has ABS but a van though...)
Also, what I do is that press brake pedal, then release, then press again. It would help dissipate the heat and helps brake life.
As for the necessity, I guess it's 智者见智 as even manufactures have different views.
To me the most important thing is defensive driving. KEEP a SAFE distance from the front car, and project likely hazards ahead...