Before I start, I'd just like to say that I am not threadcrapping, just sharing information pertaining to the thread that might affect people's decision to purchase, which is pretty important. Even though skarydrunkguy's remark seems rash, he is closer to being right than anyone else. I will share my story past weekend as well as most of my knowledge on this topic, whether you will believe/listen to me is, obviously, up to you. And just to give some background, I am very enthusiastic about driving, and so I did all the research I can find about radar/laser/etc. and tried out some top equipment, yet I still failed, read the Long story to find out how..
Really short story: Don't buy this detector or ANY detector. I've just been down this road, and I can honestly say it's not worth having.
Short story: No detector less than $300 is worth having, why do you think Escort and V1 haven't dropped thier prices in years? And a cheap detector will actually cause more harm than good because it will false like no other, and cause you to get used to ignoring it, and when there's actually a cop monitoring speed, it will warn you way too late (or not at all, see below). Also, it is impossible to eliminate false alarms on a detector without eliminating its ability to pick up speed patrols. These are radar detectors, not cop detectors.
Long story: This past weekend I was driving up to MA and I had the latest Escort Solo S2 Radar/Laser Detector, which is basically identical to the Passport 8500 except the S2 is cordless. For those of you who haven't done the research, Escort's 8500/S2 basically always win first or second in all the top detector tests; it's up there with the Valentine1. Escort is known for good false-alarm filtering, and V1 is known for extreme sensitivity (so yes, V1 will false A LOT, but it's better to be safe than sorry). Sensitivity is also why the Passport and V1 have cost the same for years with no price drop, even though there are really cheap detectors, which are useless. And don't read radartest, lots of people suspect they are biased, read the test on speedzones or car&driver. Anyway, last Sat. night I was pulled over in Connecticut doing 96mph, got a $280 ticket, and the entire time there was not a peep from the detector. Why? Simple, the cop was using laser, which no radar detector can guard against no matter what the detector companies claim.
Lasers need to be aimed at reflective/flat surfaces so the cops always shoot either your license plates or headlights, which are both too far away from the detector for the detector to pick up anything. Also, lasers are usually used at close ranges (<1000 ft), because the beam gets narrower with less distance, so the cop just has to hide and shoot you when you get close. Furthermore, the only times when laser warnings actually help is when your detector picks up stray laser beams of the cop testing somebody ahead of you. If you are alone and the cop shoots you with a laser, it won't matter if your detector beeps because he's already got your speed. Instant-On radars share a very similar concept. The instant-on radar will be off until the cop sees somebody who he thinks might be speeding, then, as the speeder approaches, the cop will flick the switch and his radar will instantly turn on and read the speed, which will defeat any radar detector because there wasn't anything to detect before that moment. Just as with laser, the detector is only semi-useful against instant-on if it picks up stray signals of the cop testing other people ahead of you. So basically, stray signals are the only basis on which detector manufacturers can claim to 'protect' you from laser and instant-on, and that is not much to go on at all.
It used to be that many police depts could not afford laser guns, but nowadays laser gun manufacturers are giving depts free guns and they don't have to pay for it until they catch a certain quota of speeders with the guns. The only protection against lasers are laser jammers, and since jammers are illegal, you have to shell out about $1600 total to get a professional stealth installation done. So bottom line, as much as I hate to admit it, the cops are pulling ahead in this game, and at this point even top detectors like Passport and V1 will only be effective against constant radar, which is used less and less. I guess in the end, it is better for everyone if we all just follow rules, and cops usually won't pull you over unless you go more than 15mph over the limit. But if you have that extreme need for speed and the wallet to support it, just get a V1 and a top laser jamming system, both with stealth installation (offered at custom shops and some fancy car dealerships). So yea, take what you want from this and good luck!