I don't see a reason to not do what a driver must legally do:
have a good dipped beam* for use against oncoming traffic (may of course require slowing to fit within range), and use main beam when no such traffic. I don't see any reason for cyclists behaving differently given they now have access to a similar amount of lumens.
Except that often the drivers don't do that. The number of morons I've seen driving round Kent with their main beams on even when I'm driving a motor vehicle towards them is worrying.
I used to cycle 30-65km to college down dark country lanes in Kent. Often I'd see someone driving towards me on main beam, they would spot my light, dip their beam, and then, a second or 2 later, having realised that I'm a bike, flip back to main beam and blind me. I used to have an extra 300lm of light I could activate in this situation to drive the point home.
Many modern car lights are just offensive and operated by idiots.
Many modern bike lights can also be offensive and some operators are morons. However generally I think they tend to be less of an issue than a couple of portable suns strapped to 2 tons of high speed steel...
Dipping ones head does't seem very precise and one would only need to briefly forget and ouch to the oncomer....
*eg a good Stzvo battery lamp on handlebars mounted so as brightest part beam dipped a few degrees below horizontal, just like a car dipped headlamp.
Going from cycling in Kent to cycling in Amsterdam, I had to change my bike lighting strategy. My lights for Kentish lanes are just down right obnoxious going through Vondelpark. I still have the Hope Vision 1 on the front (and the bracket for the 300lm boosting LED Lenser P7.2), but I rarely use it. Instead I have a Smart 1/2W led on the strap of my backpack, and the red version attached on the back of the pack[1]. But even these are obnoxious in flashy mode.
I just wish more Amsterdam bikes had working lights[2].
J
[1] I actually had one of these knicked while I was cycling along. Fortunately by a work colleague who had caught up with me and found the light in blinky mode was obnoxious. I set it back to constant and she reattached it at the next set of lights.
[2] Riding home in the rain the other night, I saw a dog with lights round it's collar, but couldn't see the human. Had to take a guess at which side the lead went, and hope not to garrote myself on the lead. Human was completely dark. I found it interesting they had lit the dog up, but not themselves[3].
[3] On the same ride a pair of police horses went by complete with riders. Not having any real light beam on the bike, their reflective bits didn't reflect anything. Their florescent didn't work in the absence of any UV, and the only way they stood out in the missle was the green LED power indicators on their radios and ear pieces.