Easy to mount and BRIGHT. The only thing I don't like about these lights is the slightly offset "saddle" area that sits on the bar or seatpost. I don't understand why they designed them in this fashion. Makes centering the lights difficult or not at all.
My primary use for these lights is for daytime road riding, to increase the chances of getting motorists' attention and keeping me safer. I use one of the strobe (flashing) settings on both lights and the flashes are powerful and get noticed. The front strobe has kept a couple of overanxious motorists from pulling out in front of me. The rear flash is very effective and I am sure that it increases my visibility.
My longest ride has been around 5 hours, and on the strobe setting, both lights worked great, with no noticeable reduction in brightness over the course of the ride. The lights recharge from USB ports, so after a ride, just plug them in at the same time as your cycling computer, easy peasy. I have only used the lights once at night, for a short trip, but I was impressed with the functionality and utility of the headlight, it does an awesome job lighting up your path considering it's size. If you are looking for a dedicated night lighting setup, especially for longer rides, there are probably better systems out there with more power and a longer run time.
This light set is reasonably lightweight and easy to strap on to the handlebar, seat post or frame using the rubber strap on each light. They are water 'resistant', but you have to be sure the USB rubber plug is firmly seated to avoid water intrusion. The lights are compact and have a very clean design that is unobtrusive. It's nice to get both front and rear lights in one pack. Because they're a set, they operate similarly to one another Mounting on the bike, choosing a lighting setting (there are multiple options for flashes or constant light as well as brightness levels), run times and recharging procedures are similar for both lights. Overall, these lights are so easy to use, and so effective for getting noticed that I've made them a regular part of my daily ride gear.