How much actual time do you save by requiring a detector.
Most places you are safe at/below 9.
Is the 10 minutes you save on a 60 mile drive by going 10 faster than "safe" that valuable?
This is a silly argument. I don't speed to save time, I speed because it's fun.
The best consumer electronics purchase I've ever made was my Escort 9500ix and ZR4 jammer. With a majority of police using LIDAR, buying a radar detector alone is like using a condom with the end snipped off. The ZR4 works (over a dozen laser saves to date), but it's a lower-end jammer; I bought it as a package deal, so it made sense for me. If you have the coin, get a high-end jammer like a Laser Interceptor:
http://www.laser-interceptorusa.com/ The 9500ix is awesome because it has GPS-lockout, and you can also setup GPS-triggered alerts for cameras/speed-traps/etc.
Even with high-end hardware, you'll still want to augment your countermeasures with smartphone apps like Waze or Escort Live, which crowd-source traffic enforcement data.