I’ve not upgraded for years, so still on first generation Lupine Wilma 5 on the bars at a poxy 700/800 lumens (can’t remember what it was).
Huuuge amount of light. I’m still using a Lupine Passubio which IIRC is about 370 lumens on max. Going to have to upgrade both because its a bit dim now, and because all my mates have upgraded so I can’t see a thing when they are riding behind me.
To be completely unfashionable I will probably go for a 2013 Hope R4 because:
1) Its got more than enough power
2) I like the idea of a separate battery and head unit as I reckon its less susceptible to damage in a pile up
3) It’s made by Hope which means it will still be going in 5 years and if anything does go wrong it will be fixed without an issue
4) The price of £225 with the new standard battery is about right for my pocket