Anecdotes about whether to use flashing lights, bright lights, helmet lights, etc., will be all over the place because our experiences are different.

I've actually had drivers and passengers roll down their windows and thank me for using extra lights, especially the helmet blinkies. Helps them to see me better. And it helps to judge distance, speed and relative orientations better. Same reason why motorcycles are generally easier to "see" despite being narrow -- the extra lights offer a better handle on quickly estimating distance, orientation, speed, etc. But on a bicycle it's easier to mount lights vertically separate rather than horizontally.

My lights are relatively dim, mainly useful in low light or at night. The helmet blinky tops out at 300 lumens. The rear red helmet light is less than 100 lumens. I have one non-directional blinky with a frantic strobing effect that seems very effective. The other is directional. I set it up so it aims where I look. I've seen drivers brake suddenly when they were about to leap out of a driveway or parking lot into my path, but stopped when my helmet light hit their eyes because I looked at them.

Regarding drivers flashing their lights or honking in annoyance, that only proves some drivers are jackwads. I've ridden with too many of 'em. Mostly guys who fume and cuss the entire time they're driving, nitpicking every single thing every other driver does: "Lookit at that brightlight m*****f****r!" while he has his own high beams and entire bank of illegal fog lights and roll bar lights bright enough to play a double header ball game. Or blasting the horn the split second the light changes. Their annoyance isn't my problem. As long as they don't physically harass or try to hit me, I don't care.

And I don't run those extra lights on the MUP. That's pointless and is dangerous.