I’ve got one and use it as a headlight with a more powerful light on the bars. I have used it in its own and it’s ok but if you’re doing a lot of night riding you may feel you need another light to go with it. Always good to have two lights anyway due to shadows and if one breaks. Battery life is ok, probably around 1.5 hours on full- I have two if the smaller batteries (so 1.5 hrs per small battery). If mounting battery to helmet the small ones are probably better due to jess weight, but you can stick it in the camelbak too. The review in that link above is accurate in terms of beam pattern and throw.
The lights are well made, but with good cheaper alternatives about these days I’m not sure I’d buy another at the current price. If your on a budget I’d rather get two cheaper lights at £80 each and have one headlight and one on the bars