I've been rollin' 'em for a couple of years now, and I really like them. They're super attention-getting, and I've had more people shout compliments, point, smile, and exclaim to friends how cool they are, than I can possibly count. I've not heard a negative comment yet.

As you can see in the pic below, I've got two of the original units (i.e. not the Minis) mounted on my rear wheel, and when riding, I can clearly see the illumination on the road to my sides. I've also followed behind my friend riding my bike, and even from that vantage point, one can see the flashing from some way off, so they're definitely, incontestably, a safety feature. They give nearly 360º coverage, the exception being that narrow range when viewing directly from behind the bike or directly ahead.

They have dual intensity brightness, and the brightest setting is intense, indeed.

Too bad they don't have a remote control or an auto start/stop feature, but aside from that, I've got little bad to say about them. I'd like to see the batteries hub mounted, and the LED boards narrower, but those are aesthetic considerations more than anything.

I've been running lithium batteries with great success.