There's a lot of discussion about this on this site and others. Some swear by the V1 while others say the technology is dated, it has many more false signals and Escort has the best patents at this point. After researching it extensively I went with the SRX and use the Escort 8500 X50 on my other cars. My personal opinion is that these are better units than the V1.
There is an interesting discussion here by people who seem to know what they're talking about.
http://www.caymanclub.net/showthread.php?t=6473&highlight=radar