X band is definitely the most popular with my radar detector. i'd say 2 times out of 3 when i see a cop and my radar goes off it's X-band. i guess NJ cops haven't caught up with technology yet. i've yet to have one shoot me with a laser.
i've got a uniden, not sure of the model number, but it's the best radar detector i've had yet. i've been through two bels, and a whistler, and all have crapped out on me. the uniden has excellent response and has saved me from MANY tickets on the parkway. it has paid for itself MANY times over again.
