Get Some F**king Lights

In London, once a light is bright enough (which they are even at the bottom of the range) then spending the kind of money that could buy you a decent second-hand bike for an even brighter light isn't going to help. And is actually really fucking annoying for other cyclists. I think some people just suffer from lumen envy.
Scoot, if there is a dark section of road with cars approaching from behind then maybe add some Scotchlight to your bag or bike or round your ankles.

it is quite true that there are light that are way too bright and often annoyed other commuter, I myself was the victim of that (especially during the dunwich dynamo).

Having said that, a light bright enough to be mistaken as a motorised vehicles is a good thing, drivers are much more likely to take greater care around you, I have less drivers pulling out in front of me when I was using the Hope Vision 1 light at the lowest setting, it's bright, but it's on par with a car headlight when slightly dipped.

When the battery die and I used the small flashing light, I was surprised by how many drivers pulled out in front of me, let alone peds walking across the road without much care, the blinking light is a tiny little dot however bright they are.

I have a Light& Motion Vis 180 back light, it's very bright but it pulse instead of blink, and despite looking bright, it didn't dazzled other cyclists at all, I rode behind a friend who have one and it was surprisingly fine.

I'd says go for a good light (but not one that cost as much as a good hybrid) whose brightness setting is enough to light up the countryside road to see properly, dipped it down a bit, and run it at the lowest setting.

Having said that, Dancing James, please for the love of God, run that light of your at the lowest setting, it's very disconcerting having that bright Exposure light blinking.