i always go on the thought of a Radar detector being a glorified paper weight if you don't learn how to read it correctly or if you don't use it correctly (like traveling 100MPH over the limit and expect enough alert time to slow down).
a Radar detector has to work for you personally so you should find out what you like and don't like.
had a V1 many years ago but it just gave you a bunch of useful info on which you must take the all in account then figure out if your alarm is a cop or a grocery store.
last two cars i owned i went with a K-40 mostly due to the fact you have nothing but two led's being seen and to be honest the only things you ever need to see. combine the two leds with audio tone and your speed you should always have enough time to slow down if you need to. there are better radar detectors the pickup further down the road but i never needed something to pickup a radar in the next town personally, given the fact if i do speed its only 20 over so a K-40 will always give me enough alert time to slow down. i also looked into custom installed Bel and escort stuff but i think those are way over done on display and useless features, i want it the detector to do a basic job in a basic way all while looking factory installed.
here is a pic of the two LED's installed in my Z4 cluster, looks stock? that's the point. you have a better chance of your Radar detector getting stolen then for it to actually save you from a ticket.
if anyone disagrees with me on this subject then feel free, i am not using your detector nor are you driving my car..again its what the person feels comfortable with more then what is the best.