I have one (as well as a White Zone 5).
The Red Zone puts out a lot of light. It's quite bright, and is definitely daylight visible. It will not look anywhere near as bright as a Dinotte or a Cygolite Hotshot because it spreads the light over a much larger area - it has an almost 180 degree beam on both axes. I have a Hotshot as well. The HS is much better for visibility from straight behind at longer distances, while the RZ is brighter when viewed off axis (the RZ appears to be about the same brightness at almost 90 degrees as it is from straight behind). If you're riding on the shoulder of a long, straight highway, the Hotshot would probably be the better choice. Riding around town? The Red Zone will probably be better.
I run just the RZ at night - it's plenty bright by itself for the riding I do, and I don't want to blind drivers with HS. I use both during the day, the idea being that drivers approaching from the rear will first see the bright-but-narrow HS from a ways back, then as they get closer and the angle changes, they'll move out of the HS's beam but still see the RZ - which will still be plenty bright because it's now much closer. I also like the RZ's wide angle for visibility on curves where the HS no longer points down the road, and for visibility to lane changer's, potential right hookers, etc.
Prior to getting the RZ/HS combo, I was using a Cateye TL-LD1100. There is a definite improvement in driver behaviour with the RZ/HS combo, whether I'm using both lights during the day, or just the RZ at night. Likewise, the White Zone on the front during the daytime seems to be visible enough to almost eliminate cars pulling out of driveways and cross-streets in front of me, and allows me to save my Seca 900 battery for night.
The RZ is built like a tank. I have no worries about ever breaking this thing, no matter what I do to it - it should survive anything short of being run over by a car - and it might survive that too, but I'm not going to risk mine to find out! The mounting system seems secure enough that I shouldn't have to find out. Speaking of mounting - the beam angle is so wide that aiming is not critical, so you can mount it to a saddle bag or backpack with no problem.
I don't have any beamshots or video yet (I'm going to try to get some this week or next), but there are some posted here:
http://www.candlepowerforums.com/vb/...FLUX-RedZone-4