I ordered a bunch of these red LED blinkie tail lights. They arrived this week. I already had one on my seat post and back of helmet. But this morning I put two on each of the panniers. They were all on the flashing mode. I even though about wearing one on an arm band on my left arm. So that would make five.

And of course, I've got a high-intensity head light up front as well as a helmet mounted one.

Too much?

That could give another rider behind you a seizure.

I have 3 taillights but generally only have one activated. The only time I active the other two is either during rush hour downtown or during a rain/snowstorm. Other than that the Vis 360 covers all bases.

The other reason not to activate all of them all the time is now you have backups, so if one or two die you have more to use instead of being stuck.

In some places that aren't all that familiar with bikes, like here in South Coast MA, you need every bit of taillight you can get. If you're in Boulder or Palo Alto, a single blinkie should be fine.

Get one Bright One up High.

Well better safe than sorry!...but 5 might be a bit redundant.

Yes
Overkill

Probably overkill. But if the pannier blinkies help "widen" your rear profile (do these LEDs make my but look big?) that may help keep passing vehicles slightly further away from you; which, if you're sporting panniers, is a good thing. On my "big" bike I have folding baskets in the rear. I have basket-mounted reflectors that swing out with the basket to help mark my width when the baskets are deployed. I had used orange marker lights at one time, but it just got to bothersome replacing batteries and turning everything on and off.

I keep a bright tail light near my saddle in flashing mode. I also run a rear wheel light, which acts as a solid tail light for rear & side visibility. Same for the front... I run a bright headlight on the handlebars and a front wheel light.

I don't understand the question. What is this "Too Much" you speak of?

All the tail lights/blinkies in the world won't do squat if they're weak, dim, cheap POS's. Get a couple of Hotshot lights, or the new Hotshot Pro 80 and call it a day.

And don't use them on blink/flash mode when it's dark. Use solid and/or pulsing modes.

If I'm riding in a group at night, I try to use a reasonable rear flasher.

If solo at night, I'm a rolling disco party

Flashing lights are a bad idea at night. In a group the problem is obvious, and when solo it's more difficult for motorists to gauge your distance, direction and speed when your lights are flashing. It's better to use a combination of solid and slow pulsating lights.

One on the rack and one on the helmet is sufficient for me. Too many, and you become a distraction, which could be a problem.

I run two also, but on the rack and the left seat stay. Have thought about helmet but I prefer my rear lights to be facing rear at all times.

Setting them all on flash is illegal in most states. Multiple flashers are only legal if they flash in unison. Out-of-sync flashers are reserved for emergency vehicles.

I use three flashers and they are not in sync so, technically, I'm a scofflaw also.

I've never heard of anyone getting a ticket for violating this law, so I think you're good.

Its only overkill if one finds it diminishes the quality of their ride by making it over complicated, or disruptive to others following them by putting out too much light for conditions.

My helmet taillight is a L&M Vis180 Micro, so even if I turn my head, it can still be seen, and is the pulsing type of light. Helmet mounting in combination with rack mounting is good, because you are easily recognizable as a cyclist from a good distance away. I do the same for headlights (helmet/bars).

Cannot compare , only Contrast.

OP is in a Major Metropolitan city has to go further across it , I'm in a small town that 'rolls up the sidewalks at night',

and dont go very far..

I second this motion.

I want to see this bike at night.....

5 is overkill. 3 Is probably fine. Two on solid one on flash.

Flashing lights at night are absolutely NOT a bad idea.
In a group ride, somebody has to be at the back and in most of them, everyone rotates to the back at some point, so everyone needs to make approaching vehicles aware of the group's presence. When solo, you need to get the motorists' attention sooner than later.

There was a study about this very issue. The conclusion was basically flashing lights are more noticeable from farther away. They do make it slightly more difficult to judge distance. However, the sooner a motorist knows you exist, the better.

Keep in mind, the majority of flashers are mostly washed out by a car's headlights, once they are at a distance of needing to judge your speed. At that point, your overall visibility (read reflectivity) takes over.

I suppose the ideal setup would be a flasher and a solid light, while still wearing reflective and hi-viz clothing.

I typically run 2 or 3, one blinking and the rest on steady. I could dig around and find the article, but I've read that having only blinking lights can mess with the depth perception of an approaching driver. They need something steady to look at to be able judge distance. I think this is even worse if the blinkies are very bright strobes.

I am now low to the road and like night rides.

5 Dinotte Tail Lights.

At least you are going to be slow, so other riders won't be behind you for long. If that was my rig, I would mount one light up high on a pole.