Got some, love them. I've actually got two Flares, as I bought one when they first appeared then got another in a Flash/Flare bundle because of the rechargeable batteries and charger.
I have them on pretty much all the time when I'm riding, day or night, they are easily bright enough to be seen in daylight and, again during daylight, the fact that they don't flash to dark means that you do have something constantly there to catch attention.
However, whilst they are fantastic attention grabbers, I wouldn't consider them to be a "see" light as Gaz says. The light is fairly scattered, and covers an arc of over 180 degrees, so you can be seen from any angle (with one front and one rear) but they don't put out enough light to give carefree night time riding.
In fact, I've just come back from a ride (yeah, sorry about the smell, I'll take a shower soon

) and I did ride briefly with just the Flash. It's just about ok at around 10mph but you quickly overtake the shadows at much above that speed.
That said, I think that the Flash/Flare combo remains a fantastic pair of lights at a very good package price. They are incredibly small, lightweight and convenient and, again supporting Gaz's post about running two lights,they make an excellent second pair.