I tried several others and after reading several commenst bought a V1, then added a second for my wife.
The arrow indicators and "bogey" counter are a real plus and help you find hidden radar traps. There are other detectors with voice, etc but the arrows and counters are not a gimmick, you learn to rely upon them just like your mirrors.
They have paid for themselves at least 10x over, even if you don't speed by much they help you be aware when the group in front of you is going to nail the brakes. We use them in all of our cars, why not?
Good luck with whatever you purchase but my recommendation is the V1.