I've had a play about recently with some lights – overall I was impressed with what was out there – if money was no object, I think I'd go for a set of Ay-up Adventure V4's, then Hope Vision 4, Lupine Wilma, then Exposure Diablo, then L&M Seca Race and then a Deal Extreme P7 torch.
If money was an object, then it would be the Deal Extreme P7 torch and a half dozen or so batteries – for the price, you don't get anything that comes close to light output and usability. Major drawback is that it come sfrom Hong Kong so any issues take a while to sort but the upside is it is cheap enough that if there is a problem you can get a new one.
The Hope gave a very good light that was very usable but it started on the lowest power setting each time – whcih was a pain as you had more clicks to get it to the setting you had previously, also the brightest setting made very little difference to the second brightest setting.
I don't think you can every buy a duff bike light now as they are all very good, but it comes down to budget and burn time…most of the big players lights only last 3 or 4 hours on full burn (although the Ay-ups seemed to last way beyond their stated run time – 5 hours for the Half-Epic (3 hr) battery and 10 hours for the Epic (6hr stated run time).
The Ay-ups V4 seems to give the best options for various situations – very good burn times, very usable light output and the lamps were very flexible…if I had the cash I would buy them without hesitation…but as I don't have teh cash, I've got a DealExtreme P7 light – which is very good.
Just my own view on the lights I've had a chance to try out over the last few weeks…check what your maximum budget is, then decide what you want out of a light – if it is turning night into day then you want a very bright light, but that could have an impact on burn time – if you don't mind the shadows then you can extend the burn time…