I've had three radar detectors in the 23 years I've been driving. First was a cheap Cobra model that saved me a couple of times, it was stolen out of my car nine years ago. I bought a $100 Uniden to replace it a year or so later, and then I bought a Valentine 1 about 5 or 6 years ago, used it for less than a year, and sold it, still have the cheap Uniden, I've only used it a couple of times in the last 8 years.
From the time I was 16 until I hit 30, I averaged a speeding ticket every two years or so, I received two tickets while using a detector, one was with instant-on radar when no other cars were around, detector went off, the cop had me. Another time I was nailed with laser, saw the cop, slammed on my brakes, he shot the laser at me as I was decelerating, detector went off, nailed me for 14 mph over.
I received my last two tickets when I was 29 and 30 years old, haven't received one in the 9+ years since. I've been pulled over for speeding 3 or 4 times since then, just received warnings though, age and a clean record have a lot to do with warnings vs a ticket. I have some fast cars (two V8 Mustangs and a turbo Subaru) and I still often do 10-12 mph over the speed limit, but I've found situational awareness trumps a detector about 95% of the time, at least around here where laser is favored by the highway patrol.
If you have to get a detector, I'd recommend a V1, but anymore I tend to stick to an acceptable amount over the speed limit (usually 10 mph), and stay aware of my surroundings, and when I feel the need to go a lot faster, I'll do it on a drag strip, road course, or deserted country road at 3-4am.