I run a Hope Vision-1 for road riding, on,low, and two of the on high are more than adequate for blasting around Sherwood, but that’s not very techy. I like them because they take AA batteries so are easy to keep going on longer rides, none of this ‘range anxiety’ nonsense. About £60 new off fleabay, cheaper used.
For racing bigger is better, how fast you can go is really determined by how well you can see rather than how fit you are. I like the Full-Beam X-12, 4,500 lumens on full whack (about 3x as bright as a typical car headlight) and reasonable battery life, two batteries get me through a 24hr race (might need more for the ‘Puffer!) Not cheap at all though.
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[EDIT] Jambo, I had some of those! THey were truely dire, even when new.