they're ok...
I have these lights and as of right now they are broken/malfunctiong. I have a few complaints about them. First of all if you are going to use the mounts that come with them I highly reccomend you somehow secure the light unit to the mount in a more permenent way than thoes little black tabs. I found that when traveling around 30mph, if you hit a bump the lights can fly off. Next, the lights arnt very useful in the daytime especially, when they are in direct sunlight because the blinkers simpaly arnt bright enough. Also, you can never tell when the thing is blinking, since there is a sort of colored plastic window to the blinker chamber on the top of the front light unit. the sunlight is always shining directly on it so its hard to tell if it is lit, unless you shield your hand over it and stand directly over it or if it's a cloudy day, and yes there is no sound. My final complaint is that they are not to be exposed to rain, but, that is said in the manual so I guess you can't have everything.
Just my experience with these lights. Personally I stick to the reflective jacket, and a blinking reflector wrist slip-on if I ever need to go out at night.