I have had many, many lights. I use both front and back lights for daytime riding, as well as night riding. Right now, I have 2 lights by Exposure. The "big boy," is the Toro, which has an incredible # of lumens, variable settings that are easy to change, and a great blinking mode. This is the light I use for truly dark rides. Most of my dark rides are before sunrise, so I like this, because I can have 2,000 lumens at 5 AM, and switch it down to less lumens, or blinking mode as the sun rises. The model I have for daily use is the Sirius. It is much smaller, has blinkie, high beam, and regular beam modes. I use it on the blinkie mode most of the time, or full mode, if it is cloudy, rainy, etc. Both lights slide on and off the same simple clamp that I have installed on the bar of both my bikes. There are no wires or battery packs to put on the bike and the lights can be charged in a USB port or charger.
I live in an area with few street lights, so it is really dark when I ride early in the AM. When I commute, only part of my ride is well lit. We bought both of these lights on line, after much research. They are not cheap, but definitely the very best I've had. I've had the Toro for over a year, and the Sirius since the beginning of this season. Since I started using the Sirius for every ride, daytime included, there is a noticeable difference in the way cars waiting to pull out of side streets see me.Both DH and I started using the lights after his crash with a car that turned left in front of him. Truly worth it.