I have been using the Escort Passport 8500 for about a decade, and I cannot count the number of times that it has saved me. I try never to leave home without it. It is way more important than my Amex card. I even travel with it for use in rental cars.
I will note that after ten years it is getting a little tired. The cord wrapping is falling apart at the RJ11 connector, and the window mount internals have come unglued. I have patched it back to life, but a new one is probably in my future. I have gotten my money's worth. I paid about $250 from Crutchfield back in the day.
'06 XK Limited, 5.7L, QD II, Black, 163K
'02 WJ Overland, 4.7L HO, QD, Inferno Red, 126K