These lights (I have the 600L-Li headlight and the 140R-Li tail light) have changed my life. They change how and where I am comfortable riding. They actually illuminate the road. You can clearly see my tail light during daylight hours. I can ride about 25mph without feeling like I'm going to outrun my headlight. Cars give me more respect/passing space. I've heard people say after I passed "I thought that was a motorcycle."
My headlight is so bright that it can trip red lights to turn green (if they have the light sensor). There are some traffic lights that have a sensor on the top that detects headlights from oncoming vehicles so at night they can be tripped by shining a bright enough light on that sensor. I was thrilled to learn that I could do that with my new headlight. I used to have to go press the pedestrian crosswalk button. If I time my light shining right, I don't even have to slow down. Sometimes I can trip a light by putting my wheel over the sensor that's cut into the pavement.
The lights are really high quality. The batteries mount to my bikes with a big velcro strap and the lights each have their mounts. The headlight mount swivels left and right and I have it set up so that I can push it up and down. The light has 6 settings: 3 flash patterns, low, medium, high. There are 2 buttons. The right button changes between modes and the left one always brings the light to full power. It's really nice to be able to switch it like that.
I like the versatility of being able to mount the headlight to my helmet or handlebars and I can easily switch between bikes.
The only downside is the battery life. I can usually ride them for about a week without recharging, but sometimes I have to do it every other day, depending on how much I have them on. It's nice that if you start to get a low battery, you can lower the power and get a lot more ride time out of the battery.