Blink, living in California as we do, you need to be concerned primarily with detection on the Ka band as that is what is used by CHP and every municipality that I've encountered driving through much of this big-ass state.
You'll be ok with any decent detector made by a reputable company as most have decent Ka detection. That being said, my experiences are as follows.
CHP drives around with their radar on about half the time. Those with it on are on definitive hunt and kill. A good detector will allow you to avoid these. CHP with the radar off will turn it on if you happen to fly by them without seeing them. They prefer to get a radar reading to cite on your ticket and without following you for a period of time, they obviously can't get an exact fix on your speed. This has happened to me
three times in the last six months, and each time the cop got on his microphone and told me to slow-down (which I of course did when they turned their radar on), I was lucky...but it's pretty embarassing
. The municipal cops seem less concerned with speed enforcement, although most large forces operate a traffic division (they drive the annoying cruisers without the light bars on top).
I'd rank the threats as:
1. CHP motorcycle cops - They have Ka radar on their bikes (no clue how they manage this). It seems less strong, but you have alot less time to react if it's radar from a bike-cop. Of course, many bike cops don't need to use their radar because they're so hard to see in traffic. On this note, if I see an unidentified bike headlight coming up fast I always slow down until I can make it out. Usually it's not a cop, but it has been enough for me to take note.
2. Traffic division cruisers - for the reasons stated above. Although they usually have their radar on.
3. Laser usage - which was reported on PPBB in the LA area and will probably be coming to a municipality near you. Radar defenses sold in this country aren't real effective against Laser - if you're getting a reading, it's too late. I saw an interesting episode of 5th gear recently about anti-laser devices, as laser is more prevalent in the UK.
I have a V1 and would suggest the same, because the arrows are so great and the detection quite good.