which would be nice. My detector has an issue in this regard
927489
Works as advertised.  It is a bit bigger than I was expecting, it's about the size of a flattened golf ball, and fairly thick.  The battery it uses is also fairly thick, but hopefully that means it will last.

My only complaint about the device is that it does not warn you if it loses a signal to the radar detector, which would be nice.  My detector has an issue in this regard, but it may not affect others.

I can assure you all that unless someone is shining a laser in your eyes, the LED is bright enough.

If you read Radar Roy's review of this device, he forgets to mention that he's the manufacturer of the device.  His assessment is fair, I think, but FYI.
2879639
The odor detector is sensitive enough and works well when you cooking etc, but the dust detector doesn't seem to function as good as the odor one, unless you use it on a construction site with visible heavy dust.... Really disappointed since I want to use it for my nasal allergy to dust.
882697
I would give it 5 stars because it is the best detector out there - hands down. BUT dealing with customer service is not such a pleasant experience. Hang up and call back if necessary until you can talk to the younger lady when she answers, otherwise "they" will spend all day being rude and telling you it's your fault. I am considering another detector only due to customer service. There is no reason these should be so expensive anyway. When I pay $400+ for something and it doesn't work right I want someone willing to help. I've used V1 for over 10 years and I know when it isn't right. You should also know that when cops change radar types you must upgrade which is only a little cheaper than a new one. So you can count on that every few years.
UPDATE: They sent a replacement and it worked. So it was not my "plug" as the woman at V1 insisted. The units have always run hot but I now suspect them shorting my electrical system. My battery has gone dead several times after leaving the unit on. It runs hot but the woman that answered the phone at V1 said "it's supposed to be hot." Yea, right.
I imagine I will change detectors next year.
3918275
Detector does falls off once in a while. That's because it  does not  Mount like factory, it  squeezes the detector.
2040788
My previously installed detectors had been First  Alert, but were only of the ionizing variety,  when upgrading, I chose the same brand.
1147247
To simplify installation I had ordered the old model of alarm so that it would fit into the same bracket as the existing broken detector.  Without any notification or apologies this vendor sent me the new model, with a different installation method, instead.

If you look at the other reviews you will see that this has happened to other people as well.
4347538
Motion detector does not seem to work too well. It lights up without any motion.
170789
Not always accurite, have gotten detects when there is no lightning , App on my phone is more accurite and reliable.
1906099
Has both types of detectors: photoelectric and ionization. Beware of fancy detectors without ionization. 4 stars because one failed in one month, but gets 4 because it alerted the failure with a chirp. New battery did not help.

May not meet building standards. For example, in 2018, Maryland will require a sealed battery or hard wire. I'll update then. I wish they would also require dual detection. I challenge anyone to find a dual detection sealed battery detector.
3347934
For the price, you shouldn't expect too much from this radar - and in that regard, it delivers.  Prone to false positives and sometimes no warnings at all (although it is hard to gauge that outside of testing that with another detector in another vehicle).  Unfortunately, the device lacks any kind of ability to program away the most likely to give a false-positive (and useless) feature - the safety alert.  It is incredibly sensitive and goes off with false positives every day when I go by overpasses.  Totally annoying and lacking in the ability to turn off the features you don't want.
430126
Light isn't bright enough, but main issue is the sensor which turns it on: it is sometimes too sensitive and sometimes not sensitive to any movement at all
780294
At first I was very happy with this device, but I've recently noticed that the readings on dust are erratic.  I can be reading in my room, with a really great score showing on the machine, and moments later I'll see that the red light is on and the score has plummeted.  The first time I noticed this, I launched the app to see what was going on, and saw the dust reading go from zero to 80, then descend in increments until it was back down to zero, all in the course of a minute.  All of my doors and windows were closed, I was home alone, and I hadn't moved except to turn a page in the book I was reading.  There was absolutely nothing going on that would have kicked up the tiniest bit of dust (and there was no visible dust in the room, as I had thoroughly vacuumed and dusted the day before).  Since then I've seen the same sudden spikes in dust readings occur, with the reading returning to zero after a moment.  I don't have much confidence in the unit.
3771294
First Alert makes a very good and reliable product. Simple to install. Arrived within a short & reasonable period of time. But and this is a big But. I ordered five of these detectors and five arrived. Four of the detectors were fine, but one was an open box item and the red tab on the back of the detector you pull to activate the battery was missing. I wrote the manufactures date of manufacture to replace the detector TEN years from that date. Just a heads-up to others
3289268
Very bright light and feels sturdy!  Would have been ideal had the motion detection aspect of it worked.  The motion sensor is not easily triggered off by motion, in spite of the nob being at the maximum setting.  In addition, the adjusting nobs are a bit flimsy and rotate past the maximum limit making it uncertain to know which point is the maximum level.
3946143
Makes me feel better.  Sometimes my kitchen range is left on unlit. This hasn't happened since I bought the detector.  So it hasn't actually had anything to detect.
4317166
It's nice and bright.  The motion detection on the second one I bought seems to be less sensitive than on the first one.  You may find that better or worse for your application.
4895734
so, one detector does not work out of two
didn't purchase to hopefully have one work.
 i want a replacement. this was for my 88 yr. old deaf mother who lives alone 2 hours away. i could not take care of her re. this on my visit this week
please help for next visit - thanks