On a trekking bike (my commuting bike) I'm using B&M IQ2 (dynamo, lamp on the fork), and Roxim RX-5 on the bar as backup/supplement. German StVZO did a great job defining how bicycle (public road) light should look like. Thanks to the StVZO compatibility I've got far-reaching beam without blinding anyone who passes next to me. On mtb I've got two XM-L (~1000 lm/pcs) flashlights. Great in the forest, poor on the road. I've to compromise far-reaching beam otherwise I will blinding other road users. Polish road traffic law doesn't require any special lights ("tactical" flashlights are not forbidden), but safety and common sense first.