[Aerkuld]

I have the Passport 8500 and it's saved me a few times. I haven't tried the V1 and the arrows look useful, but as far as I'm concerned just knowing someone has radar on will slow me down, I don't need to look around and find out where they are. If you feel the extra $100 is worth it to know where the radar is then go for the V1, otherwise get the Passport.
I will repeat what someone else said though, don't make yourself stand out. If you're sitting out in the left lane and the only car overtaking you draw attention to yourself.